picture attached for couple of folks who asked about the differences between dropouts. The picture shows the "claws" (dropout attachments) instead of the dropouts integral to the frameset, but it makes the points. Different fore-and-aft positions, different arrangements for derailleur stops, and different drop-out center line to derailleur mount center. From L to R, Campy, Shimano, Simplex Prestige/Criterium, Huret. Happy to send to others on the list.
Hope this helps see why Campy and clones are unhappy fitting on Huret dropouts, and sorry it took a while since the discussion of derailleurs for Schwinn Sports Tourers.
What I don't have is a picture of the various adapter washers with tabs that Huret made available with the DuoPar (and other models) for use with different drop-outs. That picture or schematic would be nice to see.
harvey sachs
mcLean va