The beginning/end frames are all I really need for cutting, and I certainly hope I've already got that covered. Framing differences don't interest me very much--as far as I can tell, all the technical aspects of the Sony transfer were done to very high standards and I'm not inclined to second-guess any of them. It's really just the content changes that concern me.
All I really need at this point is some sound samples that bridge the cut, so I can either re-create it using the Blu Ray audio, or splice it into the Blu Ray audio to cover the transition, whichever ends up working best. Besides, the dubs & subs angle is where things can get really fun, assuming it works at all.
Re: Superman, you may be right. I seem to have missed this. Yet another boxed set I need to buy just for one disc... which I suppose was the whole point... grr...