Where would be a good place to get new parts, or good old parts? One thing I have not mentioned, is that when it came back from the shop I had to adjust both limit screws to get the shifting to work well again- it seemed that the rings moved closer enough to the frame to require this (it would jump off the large ring and would not reliably drop to my granny).

Yea, I have probably ridden the bike too much with this issue. It is my only decent road bike.