Baronlando said:

Most of it could still be used but some of the shots would have to come from other sources, which is not uncommon in restoration. (Or they could ignore the negative and use something else, like the Blade Runner '82 blu-ray)

I find it very difficult to believe that THX COULDN'T do a proper restoration, it's a question of the cost and Lucas' willingness. I also find it pretty difficult to believe that there isn't a usable negative that could be used to restore it SOMEWHERE. Still, we're tilting at windmills, in any case, since it's never happening. I am sort of surprised they didn't do something for the 35th anniversary this year, just like they didn't for the 30th. What did they do for Blade Runner? An example, incidentally, of how Star Wars should've been handled, but that's beside the point.