Finder of things, Doer of stuff
I believe @Bandit LOAF got his hands on the original WC3 Tapes. If so that would require a lot of money to convert them to digital and they may only the the shots with the Green Screen which would also require the back ground to be inserted as well. Personally I would donate to the tape to digital transfer if that were possible.
I don't think so. The source tapes are maybe out there somewhere but LOAF doesn't have them. We have an assortment of other footage and tapes but not the original WC3 masters.
Edit - On a completely different note, the SGI machines that Origin used to create the backgrounds were capable of putting the backgrounds into the shots realtime as they filmed. You could see the actors in front of the backgrounds on the soundstage monitors. It's possible they filmed it straight greenscreen but the test footage had both the backgrounds in some shots and the greenscreen matted out to just black for most bits.