5.1 AC-3 on LD came out before 94/95 (I found a review of a Pioneer LD player with AC-3 RF output from late in 1995 and the Star Wars SE LD set had AC-3 5.1 audio in 97). It would make sense if the 93 mix involved remixing the surround to be two channel. The resulting Dolby Stereo mix would be downward compatible for 4 channel systems and be compatible with the current 5.1 systems then in theaters. I just finished adjusting the audio levels of the trilogy from the theatrical release to the 93 release and the 93 mix surround didn’t have the same signature that the theatrical and 85 did. There were a lot of subtle differences in the mixes so I may just have been imagining it, but it very well could be the first 5.1 mix of the trilogy. The audio levels seemed a lot closer to the 97 SE - what I was using to set the channel audio levels.