I wonder how much of the RIC can be upgraded with the materials we have, keeping in mind that some of the footage common to the Donner Cut and the RIC is processed differently between the two (something I learned during a previous attempt many years ago).
Well, Booshman did manage to sort of reconstruct the extended breakup scene from the TV cut, and reconstruct it pretty well. Somebody also managed to do the TV version of Lex’s Fortress of Solitude scene, and also the extended version of the Metropolis battle. It’s possible, if not very difficult, to composite the missing bits of the TV footage with the widescreen bits from the 2006 DVD and so on.