Finally for a bit of time to break the chain, remove the Grand Sport rear derailleur, and have a look inside...


My derailleur was set up with the spring tab in the middle hole of the cage. And, for what it is worth, as I was going through boxes, seeking stuff to sell, I stumbled across a NOS set of Campy ball bearing Grand Sport pulleys. Yahoo!


And, took my Rabeneick out for a little spin and the GS transmission worked just fine...


So, the next thing to do is assemble the derailleur, take the frame set to a local shop and check derailleur alignment, then put is all back together again.