Not sure of the etiquette of bringing back old threads but my post should clarify some comments in this thread (or not)
NOS frame example of a Vainqueur with 531 Pro tubing, purchased from Europe quite some time ago.
I was too fat at the time to build it up and ride it
was well over Gitane's recommended weight of 70kg's. Was not aware of that limit until after I received the frame.......
Made in France sticker
87/88 Pro build frame with 531P Tubing and Vainquer paint scheme. So,despite not being in the catalogue Gitane did make some 531P
531P labelling
Bottom Bracket
Build Docket that came with frame