Despite what the first respondent said above, I think that Jeunet was a quality bike; they just didn't have a racing team. I have one, and it's a handsome bike, with classic details. Your Jeunet is most likely constructed of Reynolds 531 double-butted tubing -- that's a good thing. They had tubing decals on the seat tube, just below the top tube, and on the forks. It probably has Simplex dropouts, and as Poguemahone says, no integral derailer hanger. I will bet it has a TA Cyclotouriste crankset, which is one that's sought by vintage bike fans. If you don't want to restore it, you can sell the frame to a teenager or college student to make a fixed gear bike out of, and the crankset will fetch something reasonable on eBay. The rear derailer is no big deal -- if the rest of it is OK, you could just replace the jockey wheels; or better yet, get a Suntour derailer: Vluxe, Cyclone, or whatever, with a hanger. One of those should not be too hard to find.