Very cool. I had a Stronglight crankset in 1974. Totally wore out the rings and had to replace it, but I loved that crankset. Can we see pictures of the hubs, rims, and spokes? Please? I looked up those derailleurs: Huret Challengers. A nice step up from the Huret Alvit that came on cheap bikes in the early 70s. I'd guess the bar end shifters are Suntour and didn't come original on the bike (maybe a shop swap at time of purchase). Whatever you choose to do with this bike, it will be sweet.
Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72