There is also a very high quality theater reference version but not by belbecus, obviously not as good as the laserdisc.
Then you have the VHS rip floating around of the rental tape captured by thestarkiller.
That along with the 2 or 3 sources for the mono mix the only mix missing is the 70mm.
I think its pretty much been confirmed the 1997 special edition was not based on the 70mm but was derived from the same six track master used to make the 70mm version.