So,
Do folks know, did most of the older Gitanes have French bottom bracket threading, or did some of the models have standard threading?
I know having the year, model and maker of the dropouts would help greatly here... I will check tomorrow and post that info. I do know its Reynolds 531 or 501. Decals are rubbed off pretty bad. Its says handmade in france, has big foil decals and if I remember right, simplex drops. No derailleur hangar and a big u shaped bracket for the rear brake cable brazed onto the top of the seat stays.
I'm building up a Gitane frame which was donated to a shop I worked at.
The reason I ask is that a standard thread BB fits, but feels loose once it's threaded in. Could someone have retapped a french BB to standard, or would that just have become a total mess? I know sometimes folks re-tap standard BB threads to italian when they are super messed up.
But since standard and french tpi and diamater are so similar... just R and L hand threads, It seems if someone tried this it would just be a total disaster.
Ideas? If the BB threads are messed up, what to people think about the replacement Bottom Brackets that thread onto themselves? Are those a bad Idea?

They last used the foil decals in 1973. If yours has foil decals, the Reynolds tubing is 531 and it has or had French threads. Some of them had Simplex dropouts with no hanger.

Velo Orange has a threadless BB that will work if your theads are unuseable. Have you tried French bottom bracket cups?

If the threads are messed up the threadless BB mentioned is a good way to go - albeit a little expensive. I installed one this past spring and its worked great.

See: https://www.sheldonbrown.com/gloss_bo-z.html#bottom

British 1.370" X 24 TPI , right side uses left hand thread
French BB diameter 35 mm = 1.378" X 25.4 TPI . both side uses right hand threaded

French Shell is slightly larger than English BB but thread pitch is slightly finer.
Left side may seem to fit, but will be loose. If the Left (adjustable) side starts but then the threads bind, it is probably still a french thread shell. If the BB cup threads all the way without any binding, someone probably forced an 24TPI BB into the 25.4 TPI threads. The right side of french threading is opposite direction of british, threads shouldnt even start. It would be a total mess if someone were to have tried to re-thread the right side to british threadeing (completely changing the pitch and direction of the threads). If any re-threading was intentionally done by a competent mechanic, more likely that they re-threaded the french shell to Italian, this actually makes most sense because they are both all right hand threading, only the pitch and diameter change. Sheldon indicates however that the british threads are too small diameter to engauge in a larger diameter Italian shell (though pitch is same 24 TPI for both). .

I'll bet that there's nothing at all wrong with the threads and you screwed a british-threaded cup into the non-drive side, found it to be loose and decided that there must be a problem. What you need to do is try some French cups. If you don't have access to a set to try, I'm also in the East Bay, CA.