Wow, that is a Campy Gran Tourismo in the back! Over kill for the gearing you have. The only place I ever saw another one on a bike is when they came standard equipment on the Schwinn Sports Tourer. I had one as kid and have an old blue one now from 1972. They are the most hated derailleur Campy ever made but I never had any problems , other than it tends to jump two gears at a time if your not careful. I like mine because it's shiny and original. Those little red "C"s are cool too. Whole Articles have been written about those Campy GTs , so I'll stop here because this is a Univega thread.