Originally Posted by wrk101

Modern chain is fine. Unless you REALLY have to have an old NOS freewheel, IMHO, I would buy a NEW 5 speed freewheel instead. NOS term tends to be grossly overused, and given to non-NOS parts.

I have on occasion had skipping due to other reasons. Most recently, it was a bent derailleur hanger. It was not obvious! But once I put my tool on it (Park DAG), it was not straight. In this situation, I had a brand new freewheel and new chain, so I knew those parts were good.