hairy_hen said:

I did listen to those raw recordings, and the surrounds can't be heard there either. But I think those are what Belbucus used to make the 70mm/1993 comparison track, so it's not surprising. Separating the comparison channels and playing them back individually, it seems quite clear that the theatre where the recording was made did not have an operational surround channel. The front channel portions of the '93 mix when folded down to mono seem to match up exactly with the recording, in the levels of certain surround effects that were also partially panned to the front, which really confirms my suspicion.

No doubt about those missing surround effects, just a late reply...

No, Belbucus 70mm/1993 comparison track was made from a recording of a 70mm engagement from 1977 at the Loews Astor Plaza in New York City, with occasional patching from another 70mm recording at the Loews Orpheum. morgands1 recording however was done in 1977 at the Paramus Triplex in New Jersey. And we also have a third source that I mentioned earlier done by L.Mayer (Mrs. BrianM) recorded in D.C. which I haven't heard yet. Need to track that down...