Many thanks to dlbsyst for helping me navigate the treacherous waters of usenet! I've got II and VI safe and sound, will get on the others soon.

Since I've just had a tinker with VI, here are my findings in case anyone else is planning on doing a project:

The picture is actually 2.00:1 ratio, which is less wide than the supposed 2.20:1 of the 70mm screenings. It also has some extra lines at the top and bottom (some broadcast junk added by Sky no doubt) so it is in fact 1920x1088 - this needs to be trimmed for BD compatibility.

x5gb was right on the money with the video levels - if you set the input levels to 16 - 235 in your colour corrector, you'll get the proper black to white range (and a generally pleasing colour balance).

The frames are a perfect match to the BD video, but the video is missing exactly 2 seconds of black at the start - bear this in mind if you're using another soundtrack (such as Buster D's terrific PCM rip).

Other than that, it's a very nice and filmlike presentation. Thanks to everyone who brought these captures to our attention!