A lot of the early Résistance mouvement had involvement from the far-right, yet there doesn't seem to have been much in the way of a legacy left in the modern far-right. The modern french far-right has rather been built around people like Tixier-Vignancourt and, of course, Jean-Marie Le Pen that had a deep fondness for the fascistic Vichy régime, with barely a mention of this "resisting" far right. Why?
It is true that people from the far-right joined the Resistance, and it is also true that some in the far-left ended up in Vichy (or worse). Simon Epstein, in Un paradoxe français (2010), has shown that not only both attitudes did exist, but that they were more common that it is usually believed. Many people, of course, followed a more expected path, ie fascists in Vichy and progressives in the Resistance.
In the case of the far-right-activists-turned-Resisters, the biographical notes in Epstein's book actually answer the question: those who survived the war did not disappear at all, but went on with their careers, their pre-war past more more less forgotten. Before the war, these men and women had been ultra-nationalists, antisemites, anticommunists, violent activists, supporters of the Action Française and of its founder Charles Maurras, members of the Camelots du Roi, of the terrorist organisation La Cagoule, or of the nationalist league Croix-de-Feu. After the war, they were "whitewashed" by their Resistance activities and most were able to reinvent themselves, or at least to hide or put their past behind them.
Here are some examples:
Hubert Beuve-Méry: he participated in violent demonstrations of the Camelots in 1925 and was briefly attracted by the fascist party Le Faisceau. During the war, Beuve-Méry was head of studies for the Petainist Youth University Ecole d'Uriage. Beuve-Méry joined the Resistance after the school was shut down in 1942. In 1944, he founded the newspaper of record Le Monde at the request of de Gaulle, and ran it until 1969.
Marie-Madeleine Fourcade: in 1936, she met the right-wing activist and officer Georges Loustaunau-Lacau, for whom she ran La Spirale, a nationalist, anticommunist, and antisemitic publishing house. During the war, she helped Loustaunau-Lacau to set up the Alliance spy network (which was working for the British Intelligence Service), and ran the network herself for the rest of the war after the arrest of Loustaunau-Lacau in 1941 (he was sent to Mathausen in 1943 but survived). After the war, she supported de Gaulle and had an important role in keeping alive the memories of the Resistance.
François de Grossouvre: close to the Action Française before the war, he joinded after the Armistice the Service d'ordre légionnaire (SOL), a paramilitary Vichyite militia, founded by Joseph Darnand, a Cagoule activist and later a Waffen-SS. The SOL motto was to "fight democracy, Jewish leprosy, and Gaullist dissidence". De Groussouvre left the SOL in 1943 and joined the Resistance in 1944. He became a successful industrialist after the war, and, for more than 30 years, a close associate (and keeper of secrets) of socialist François Mitterrand, whom he followed at the Elysée Palace as a shadowy man of influence.
Gilbert Renault aka the Colonel Rémy, one of the most famous Resistance members. A royalist and catholic, admirer of Charles Maurras and close to the Action Française, he participated in the right-wing riots of the 6 February 1934. He was one of the first people to join de Gaulle in London in June 1940, and managed Resistance intelligence networks. After the war, he remained a Gaullist for a while and became famous thanks to his Resistance memoirs and as a writer of popular thrillers (all made into movies). He moved further to the right and ended up defending Pétain, but his name remains synonymous with "Resistance".
André Bettencourt: close to the Cagoule before the war - he was the stepson of Eugène Schuller, founder of L'Oréal and one of the Cagoule financers - Bettacourt ran a weekly collaborationist magazine during the war where he wrote antisemitic articles. He joined the Resistance in 1943 or 1944 and had a long and successful postwar career as a center-right politician (mayor, deputy and minister) and industrialist (L'Oréal, Nestlé). His past was only revealed in 1989 and he was forced out of L'Oréal in 1994.
Alexandre Sanguinetti: another former Camelot activist, he joined the Resistance in 1943. After the war, he seems to have wavered politically, and was close for a while to former Vichyists and supported of French Algeria. However, after the return to power of de Gaulle in 1958, he became a loyal Gaullist politician and a founder of the sulfurous Gaullist militia Service d'Action Civique.
Daniel Cordier: another Camelot with extremist ideas (even after joining the Resistance he wanted Léon Blum to be shot after the war), he joined de Gaulle in June 1940 and became the secretary of Resistance leader Jean Moulin, whose influence made him give up his far-right beliefs, and he participated in the creation of the Comité National de la Résistance. After the war, he quit politics and became an influential art collector and dealer, a historian, and in his later years, a gay rights activist.
We can see that that personal trajectories of these people were extremely varied. Some returned to far-right activism (notably as supporters of French Algeria) or kept praising Vichy, but many, like François Mitterrand himself, who had been a far-right sympathizer in the 1930s, were changed by the war and gave up extremism.
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