Update: I've finished going through Jedi, and it had a ton blurred/blocky frames that I've fixed. It was by far the worst of the six films in that regard. For some reason almost every shot of the Endor battle had these encoding errors. I don't know if the broadcast encoder had issues with the leafy background, or what. I'll post a sample to show what I'm talking about later.

Of the other five, AOTC was by far the worst to deal with initially, but I think I've already taken care of most of its issues. The other four shouldn't involve too much work.