That’s great, I’m glad you liked it. Discrete 5.1 can sound really good, but I’ve heard some pretty stinky ones too. The fact that these tracks have such good spatial imaging is a testament to what a good job they did in mixing them back then, and also Jim Fosgate’s genius in coming up with the design for Prologic II.

Oh yeah, the 1997 DTS might not be the best source for LFE, since it is stored in the surround channels and mixed in with other stuff. The DVD and Bluray versions of ESB and RotJ are essentially the same as the '97 mixes aside from the things that got changed later, so using the Blurays is fine for that.

The only one where the '97 DTS might help is with the first movie, since the later remixes are totally different, and the '97 bass has a better tonal quality than the DVD/Bluray. However, it might be better to just get it by lowpass filtering the stereo PCM tracks of the 1997 mix, since all of the LFE bass seems to be in there, just at a low level. Since you’d have to do that to the DTS anyway, this way it would at least not have undergone any lossy compression, although it might require more editing to get it to fit.