I'm looking for a rather odd part for my Huret Success rear derailleur. It's an add on attachment that acts as an "S" adjuster for campy dropouts. This came on late 70's, early 80's Success and Jubilee derailleurs. I also believe it was available separately.
Here is a picture of said part:
And on the actual derailleur:
It's the item marked "2)" in the picture.
San Francisco, CA