I have Campy Record 8 transmission. Recently broke the rear shift cable and replaced it, but am having trouble adjusting the rear derailleur for accurate shifting.

Among other things, I noticed that if I'm looking at the derailleur from the back of the bike, there is some play in the derailleur body left-to-right. Not in the movable part, but in the part where it bolts into the frame. The bolt that clamps the derailleur ot the frame is fully tightened...is it possible that the bushing inside is worn? Or is this normal?

Other suggestions for getting the shifting right?