yoda-sama said:

One question I have is (if a link to some other discussion is enough to explain, that'd be fine), what does this '85 home mix offer in comparison to the '93 and non-mono '77? (Okay, I also am not sure what it is '93 [definitive LD sourced, I'm sure] has that's different or desirable either.)

IIRC, '85 is basically the first stereo track that merges back in the mono mix lines like Threepio's tractor beam line. The '93 one does this too but (among other things) it adds a bunch of sound effects that weren't ever in any of the original audio mixes. So '85 is desirable because, while not technically an original track, it could be considered a merged form of the original '77 tracks. Also people remember it from home video releases and like it from there.