I have a 1971 Gitane TDF that I bought new and have just dug out for a rebuild. Most parts are still available or can be changed if needed. They came normally with simplex changes and normandy hubs but some like mine had campy changers and hubs. The srtonglite crankset shaped like a star is something I haven't seen for a while, although there are E-bay stores with french thread chranks NOS. Seatpost is an uncommon 26.4 I think. Brakes were mafac competitions but NOS mafac racers can be bought for about $35 or less for the entire set with cables,levers,calipers,etc. I would take it to a good bike shop to verify the fitment of the bottom bracket and headset. Some bikes imported during the 70s bike craze had different size fittings which were not consistent so it would be nice to be sure what you need before you buy an expensive part. I would maybe do the least expensive rebuild you can do and then upgrade components later if you like the bike and have some extra money.

Bob Skillman Ellicott City MD