Well, I do think it's safe to assume that the original negative pieces that were removed and replaced by Special Edition crap have been placed in storage somewhere. I do think that all of the original (not '97) negative were chemically restored before they did the Special Edition additions, so I think that all of the original negative would be at Disney's disposal, but I also think it's safe to assume that the cut parts are in rougher shape than the '97 negative so that could be the problems referred to in that recent comicbook.com rumor (assuming that it's an honest rumor that is). I'd imagine that Lucasfilm's warehouse is probably pretty well organized since Lucas held on to everything for those 20 years between the theatrical release of Star Wars and the Special Editions, and it hasn't even been that long since then so I'd be surprised if any has been lost, especially since the "Empire of Dreams" documentary crew supposedly had access to the Holiday Special tape, and I'm sure if Lucas wanted to destroy anything, it would've been that. I also am assuming that after that expensive restoration in the 90's the negatives were maintained better than they were back in the 80's, but that's just a guess.