This weekend I bought a box full of bike parts, mostly Campy. In this lot, a Campagnolo derailleur that I have never seen before. It looks to be the same as a Gran Sport in proportions, but has a very dull finish that I think is zinc plating. I'm sure it was a lot shinier before it spent the last 30 years in a box. No series name, just "Campagnolo" on it. No markings on the back at all.