I've seen, refurbished, sold whatever loads of French bikes over the years, and I would roughly put them into two camps: mass-produced by one of the big brands = annoying, poorly executed, badly finished and hugely overbuilt; handbuilt in a small shop with a real persons name on the downtube = marvellous, beautifully made and finished, always worth the time and money to fix them up.
Its reductive I know, and only my opinion but I never want to try and 'renovate;' a 1970s mid-range Peugeot ever again.
I have one Frenchie, which I bought from down the road as it was pretty cheap and had a pair of Phil Wood hubs on it, after collecting it from the eBay seller and having a chat and then riding it 3 miles home it was clear I'd be keeping it! It was built for her in the mid 80s by a shop called Rando Cycles in Paris, she was told that they often got other builders to produce their frames and allegedly this was built by Berthoud. It is a classic lugged touring frame with BSC headset and BB and is the *perfect* size for me, because of its 00s horrible thick powder coat and no decals it became a commuter/child carrier though, but it will get a rebuild at some point in the future.