I'm not an expert on the history of this film or the sources for info about it.
Is it possible that Lucas just claimed that the studio hacked his film apart and deleted large chunks in order to justify the changes (mostly scene order) he made to it in 1978? Is the intro video/buck rogers change confirmed by anything but word of mouth or memory?
(Also: I've got an encoding of my reconstruction uploaded (LD+Blu frame-matched to the 16mm, with 16mm audio) if anyone else would like a link by PM, to view it and give feedback, thanks)