Pseudonym: Roux, Michel
It is a very strange coincidence that Roux's benefactor Leon Gachman had Box 308 in Fort Worth and that Albert Osborne's contact in Laredo also had Box 308, especially because one of the few places Roux visited after Fort Worth and Dallas was Laredo.
Souètre was connected to Aginter Presse. 104-10322-10085, p. 6. Aginter was involved with a variety of fascist plots and developed the "Strategy of Tension", where right-wing attacks were falsely pinned on left-wing groups in a pattern designed to engender a climate of fear throughout the populace.
Peter Dale Scott writes: To the best of my knowledge, there was just one mercenary group in Lisbon, Aginter Press, created in 1966, two years before Ray apparently contacted it. Aginter Press was a highly secret group which, according to an official Italian Senate Report, was “directly linked to the CIA and the Portuguese secret service, that specialized in provocative operations."  Years ago I wrote about Aginter Press as part of a global “CIA-Mafia-Narcotics Connection” financed in large part by international drug trafficking. 
A few words about Aginter and one of its so-called “correspondents,” the celebrated Italian assassin Stefano delle Chiaie, will illustrate about the importance of the global drug connection. Aginter supplied foot soldiers for the CIA’s operations in Chile between 1970 and 1975, first in Patria y Libertad which prepared for the 1973 coup, and later with DINA, Pinochet’s drug-financed intelligence agency.  https://www.history-matters.com/essays/jfkgen/AssassinationsDeepEvents/AssassinationsDeepEvents.htm
Re 1953 and Jean Souetre, aka Michel Roux, aka Michel Mertz: "On 3/5/64, Dr. Lawrence M. Alderson, dentist, 639 West Forrest, Houston, Texas advised that he met Jean Souetre in France in the summer of 1953. He stated at that time he was stationed as a First Lieutenant with the United States Army in Petette Malioun, a small town near Rheims, France, where a depot was being established. He stated that Souetre was connected with security in the French Fourth Air Force and in this capacity extended many courtesies to Dr. Alderson and the men serving under him..." Also see 180-10110-10054, p. 28, memo from EH Mossburg at FBI HQ to SAC New York: "(Informant) on 4/3/63 advised that a Captain Souetre is a fugitive because of his activity in the Secret Army Organization (OAS, composed of many French military persons who were violently anti-de Gaulle in view of his attitude in desiring to grant freedom from France to Algeria. According to (REDACTED) Souetre received a letter from the Aldersons at 5803 Birmingham, Houston, Texas which wished him well and success..."
"On 23 May 1963, Rene Souetre, who claimed to act as external coordinator for the OAS organization based in Portugal, said that after de Gaulle, there were would only be two choices in France: Communism or the OAS... Souetre pointed out...that the OAS must be prepared to counter a Communist plot at any time, as de Gaulle was an old man and also since he could easily meet with an accident... The OAS, according to Souetre, was now trying to penetrate the French army and the Government in order to build a counter force to the Communists within the French Government... Souetre explained that the OAS intended to prevent a Communist takeover at the post-de Gaulle election by the expedient of preventing the election from taking place..." The document also states that Souetre had escaped from a French detention camp in 1961 "and subsequent to his escape he was alleged to have been involved in an assassination attempt against de Gaulle.
7/12/63 CIA memo from Deputy Director, Plans to Deputy Director for Coordination, Bureau of Intelligence and Research, Department of State, re OAS Attempt to Enlist the Cooperation of the United States for its Anti-DeGaulle Activities - "In May 1963, an attempt was made in Lisbon, Portugal by two members of the Organization de l'Armee Secrete (OAS) to enlist the support of the United States government, specifically the Central Intelligence Agency, although the name was never actually pronounced) in their operations against de Gaulle. The attempt was made was made by Captain Jean Rene Souetre and Captain Guerin (fnu). Captain Souetre identified himself in the organization as coordinator of external affairs serving under Major Pierre Sergent... The CIA representative told Souetre that de Gaulle was the chief of state of an old and respected ally of the United States, and that the US had absolutely no intention of working with any person or group against the duly-constituted government of France...Souetre is the name of a former French army captain who escaped from a detention camp in 1961. Subsequent to his escape he was alleged to have been involved in an assassination attempt against de Gaulle. Souetre was born on 15 October 1930 in the Gironde Department of France. Sergent is also a former French army captain who has been reported to be the successor to ex-Colonel Antoine Argaud, under whom he worked..."
Re Nov-Dec. 1963, (FBI urgent memo from Houston to HQ re Jean Souetre aka): "Manager, Rice Hotel, Max Peck, advised Michel Roux came to his office latter part of November or first part of December, 1963...Roux stated he was formerly in the French Foreign Legion and defected. Peck gave Roux letter of introduction to Bamer Hotel, Mexico City, and presumes Roux contacted that hotel..."
Re 11/20/63-11/24/63: 3/12/64 memo from Director FBI to Legal Attache, Paris, "Roux was in Houston November 20 last and visited (Leon Gachman, head of Gachman Metals, Post Office Box 308, Fort Worth) in Fort Worth between November 21-November 23 and returned to Houston. Through friends Gachman arranged to obtain job for Roux at unidentified Mexico City hotel until Roux could obtain proper visa..." Also see 124-10224-10060, p. 2: Leon Gachman of Gachman Metals claimed Roux arrived at his home in Fort Worth the night of 11/21 as part of his efforts to get into the hotel business; that Roux visited his son's class at Texas Christian the morning of 11/22; that they were having lunch at a cafe when the news reported the shooting of JFK. The next day, Roux went back to Houston, where Gachman joined him the next day, from there Roux went to Mexico City. Also see http://jfk.hood.edu/Collection/Weisberg%20Subject%20Index%20Files/S%20Disk/Souetre%20Jean%20with%20aka%27s/Item%2011.pdf - page 10 - in an affidavit given to French authorities, Roux recounts his trip to see "Gaschman" for work in Fort Worth and Houston that never materialized, never mentions that he was in Dallas on 11/22, is vague about the time period that he was in the Fort Worth area; said that he only said the Mexicans should "reinforce security" when de Gaulle comes to visit. - page 1 - a journalist states he met Roux in Montreal in January 20-21, 1964, where Roux told him he had recently visited Dallas as well as Fort Worth, and that there was a plan to assassinate de Gaulle in Mexico City in March 1964. Also see page 14: "Legal attache in Paris advised 3/13/64 Michel Roux referred to above has been located by French in Paris and it has been determined he is not identical with Jean Souetre. Discontinue investigation."
Re 11/22/63-January 1964, re Souetre aka Michel Roux aka Michel Mertz: A faint 4/1/64 extract of a document released by CIA (known as FOIA document 632-796) states that "Jean Souetre aka Michel Roux aka Michel Mertz - On 5 March, the Legal Attache in Paris and also the SDECE man (French intelligence service) had queried the Bureau in New York City concerning subject stating that he had been expelled from the US at Fort Worth or Dallas 48 hours after the assassination. He was in Fort Worth on 22 November and in Dallas in the afternoon. The French believe that he was expelled to either Mexico or Canada. In January he received call from dentist named Alderson living at 5803 Birmingham, Houston, Texas. Subject is believed to be identical with a Captain who is a deserter with the French Army and an activist in the OAS. The French are concerned because of deGaulle's planned visit to Mexico. They would like to know the reason for his expulsion from the US and his destination...WH/3/Biblio; CI/SIG; CI/OPS/Evans." Discussion of this document in 1977 by FBI officials and the media can be found at 124-10224-10072, p. 6.
1/31/64 report: Lola Loving, wife of Eugene Loving, told the FBI that she and her deceased husband had been missionaries in Mexico. "(in about 1956) they met a missionary by the name of Albert Osborne. This man, whom she believed was a Baptist, had a mission in Texmelucan, not far from Mexico City. His mission consisted of his own large home where he gathered in young men who appeared to have no homes or ties, trained them and then sent them out on their own as missionaries. It was not long before the Lovings found out that Osborne was using two names. His second was JOHN HOWARD BOWEN. In fact, Osborne readily admitted the use of both names and voluntarily explained that John Howard Bowen, at one time, had been an associate of his at the mission at Texmelucan but had died. Monetary contributions for the mission, which is dependent upon such donations, kept coming in to Texmelucan in Bowen's name, and rather than lose this money, Osborne had gone to banking officials and explained the situation. Specifically mentioned by Osborne was American Express authorities in Mexico City, who had agreed to honor the contributions and make the payments to Osborne, using Bowen's name. Consequently, over the years since that time, Osborne had assumed the dual identity...She recalled in recent weeks, possibly in the past month of two, she had received a letter from Osborne in Spain." She sent him donations of clothing, which had to be sent to the US because Mexican regulations did not permit such packages. "(he wrote her recently and told her "that the clothing this time should be sent to him in either name Albert Osborne or John Howard Bowen, Post Office Box 308, Laredo, Texas. Mrs. Loving said that this was the address of a friend of Osborne's but that she had never known the name of this individual.
3/6/64 urgent memo from Director, FBI (Richard Cotter and FNU Mossberg probable authors) to SAC New York, SAC Houston, SAC San Antonio: "Jean Souetre, aka Michel Roux, aka Michel Mertz...French authorities have REDACTED. WFO (Washington Field Office) has determined one Michel Roux, born August 31, 1940 at Soyaux, Charente, France, and carrying a B-2 visa, entered US at New York City November 19 last and departed December 6 last at Laredo, Texas. At time of entry he listed US address as quote Houston, Box 308, Fort Worth, Texas, end quote. San Antonio and Houston both check INS records locally. Identify subscriber to Box 308 and, if no reason exists to contrary, interview. Expedite and sutel Bureau and New York any pertinent data developed. New York should furnish any pertinent data reported by Houston and San Antonio to (REDACTED - "informant). French liaison representative at New York and French authorities in Paris are REDACTED. Legat, Paris, being kept advised of results of our inquiries." On 3/7/64, Michel Roux was questioned by French intelligence, see http://jfk.hood.edu/Collection/Weisberg%20Subject%20Index%20Files/S%20Disk/Souetre%20Jean%20with%20aka%27s/Item%2011.pdf - page 9.
3/9/64 memo: "Jean Souetre, also known as Michel Roux, aka Michel Mertz...Rebutel March 6, last, requesting San Antonio and Houston to check INS records regarding Subject and identify subscriber to box 'Houston, 308, Fort Worth, Texas'. (INS advised) no record identifiable with Jean Souetre, Michel Roux or Michel Mertz...Dallas has been requested to conduct investigation regarding Box 308, Fort Worth, Texas." Also see 124-10224-10064, 3/9/64: "Postal inspectors advised no such number as Box 308 utilized in Houston." Also see 180-10110-10054, re 3/12/64 memo from Director FBI to Legal Attache, Paris, "Roux was in Houston November 20 last and visited (Leon Gachman, head of Gachman Metals, Post Office Box 308, Fort Worth).
March 1964 memo from Director, FBI to SAC, New York: The Washington Field Office learned in the last few days that "a Michel Roux entered US 11/19/63 and departed 12/6/63 at Laredo, Texas for Mexico...Legat, Paris, advised 3/13/64 Michel Roux referred to above has been located by French in Paris and it has been determined he is not identical with Jean Souetre."