(Just to complete the excellent review of Tom Morgenstern)
The HDVS capture may have been transferred to film at the time :
Peter Wilson (from High Definition & Digital Cinema), who worked on the HDVS production of this concert, said that the tapes have been transferred to 35mm film using Sony EBR process (and then blown up to 70mm film). source: hddc.co.uk
ps : Electron Beam Recording (EBR) was a process developed by Sony PCL to transfer HDVS video tapes (1125i @ 60hz) to 35mm film @ 30fps. (There also was a mode to transfer into 2250p @ 24fps to simplify the direct distribution to cinemas!)
Do you think that there is film of three of the shows in Genesis or Jim Yukich's possession? Could these theoretically be re-edited and prepared for HD blu-ray? I wonder how well a 4k scan of the 35mm film/HDVS tapes would look. I imagine it could be stunning. I also wonder if in fact there aren't some camera shots of the In The Cage Medley from one or more of the nights since there were 8 camera men I believe. I'm sure Genesis still recorded the audio via digital multi-track of the four shows and wouldn't stop the audio recording to change tape during the medley. It would be really cool boxset if the band was into releasing material like so many of their contemporaries.