The 1997 DTS isn’t really usable for this kind of project, because there are so many additions and changes that getting it to actually fit the original versions of the movies would be a pretty major undertaking. That’s not to say that it would be completely impossible, and I’ve given some thought to how it might be done, but I haven’t had the inclination to actually try it.
I’ve found it more beneficial to simply start with a version that was closer to the original mixes to begin with, and go from there. Sure, given the available sources it has to be an upmix and not discrete channels, and the surround effects are mono instead of having any left/right component—―but the 1993 versions actually have the most dynamic range and best overall sound quality of any version out there, including the special editions. With additional bass, they sound even more fantastic.
I sometimes have to remind myself of the distinction between ‘what I think sounds best’ and ‘what is most authentic to the original release’. Usually those two things are the same, but not always. If the 70mm mix of RotJ had ever been used as a source for a home video release, it would be simple just to use that and disregard everything else; but since it wasn’t, I have to decide which elements to use when I find differences. For Despecialized 3.0 I may end up doing all the 5.1 versions over again from scratch, which would allow for different techniques to be used and perhaps even greater efforts towards authenticity, but for now I just want this to be consistent with what I’ve put out for the other films already.
Anyway, the stereo mix for RotJ is nearly done, and mostly I just need to check if there are any more dropouts or distortions to fix that I haven’t spotted yet. After that it’s 5.1 time. When I said it would take me a few weeks to get these done, that was a deliberately conservative estimate, since I didn’t want to promise to have them done quickly and then not deliver. It’s going as quickly as possible without letting myself get sloppy, since I’d really like these to be in 2.0 if possible.