Thanks, Pfr, fascinating.

Sadly it's fairly certain that the Trailer/Leader multitracks didn't survive. Too much to hope for. I reckon the tapes the B. Library have are a stereo mix taken from those, which was then used to record what became the production master. That's not how I'd have done it, but I expect they had their reasons. At least someone had the good sense to put them where they'd be stored in appropriate conditions - pity they didn't tell anyone though.

It's the artists I feel sorry for - they deserve to be told.