B-screw hitting derailleur hanger I have a Schwinn Super Sport circa 1966, that came to me as a single speed, so I have never seen a derailleur on it. When I put this SunTour derailleur on it - mid 70s I think, came off a Peugeot - the b-screw hits the Schwinn's derailleur hanger body, not the b-screw stop, as you can see in the picture. The stop seems way further forward on the Schwinn than the Peugeot. However, a modern Shimano XT derailleur seems to fit the Schwinn fine . . . I just was hoping for something  approximately period appropriate. What's going on here? Are the different style derailleur hangers? How can I know what derailleurs will fit the Schwinn?

Here's the mismatch:


I can rotate it so it hits the stop, but the derailleur position looks like it would not work, the b-screw is all the way out, not really hitting the stop dead-on, and the derailleur cage is hitting the seat stay:



However, this Deore XT derailleur seems to have a longer or slightly further-out b-screw that hits properly. I haven't put a chain on it to check, but this looks like it would work. So I want something that works like this, but is from the 60s-80s, 10-speed road era.
Upon further research it seems that in 1966, Schwinn was using Huret dropouts, which have a different configuration than modern derailleur hangers, which are based on a Campagnolo design. So the options are to get a Huret derailleur, or make an adapter like this one made from a washer or look at this thread for some other options.