Ok, sorry it's taken me a week to get back to you - here's a quick rundown of the London 70mm print. It clearly originated in the UK, having a 1979 BBFC 'X' certificate at the front (I was too slow with the camera, but at least it looked the same as my reconstructions
). It would be interesting to hear about the condition of any surviving prints in the US, if they exist. Anyway...
Picture: Sadly, the fade towards pink/brown made it pretty much impossible to say with any certainty what the print's original grading was like. That said, the overall tone of the MUTHUR room indicated the relative darkness and warmth of the photonovel and 1995 laserdisc. Unfortunately, I couldn't judge if Ash's head was a match to those sources since there was very little blue remaining in the picture.
Sound: The print's magnetic 6-track had obviously suffered some damage over the years: there was an intermittent rhythmic thump on the bass channel(s), and a persistent clicking on the right for much of the running time. Despite these bits of 'character', the sound was really rather wonderful - big and detailed, with impressive separation and terrific rendition of the music score. And hopefully we can now put to rest the uncertainties surrounding the theatrical mixes - in terms of content, this track was a fairly precise match for the BD's 4.1, NOT the 1995 laserdisc mix. It was polished and carefully mixed, unlike the more choppy and raw '95 (aka 'Sensurround') version. I guess Disclord was right on the money when he called that.
The BD's 4.1 isn't perfect - it's rather 'polite' compared to the actual 70mm, lacking the energy and loudness (and of course the bass presence) of the magnetic track, so I suspect some cleaning and processing has been done to tame its ferocity for home theater use. The acid scene - where some of Goldsmith's original score bleeds into the Freud track used to replace it (as clearly heard on the LD PCM) - has certainly been tidied up somewhat in comparison to the mag, though not to the same extent as the newer DTS mix, where it's been completely cleaned.
Those are the main things I took away, but hit me up with any specific queries and we'll see if Rob or I can remember! All in all it was a great show - hopefully the print will survive long enough for another chance one day.