That's something I almost wished the movie companies would do, ie. use CGI to get rid of the zippers and wires in cases where you weren't supposed to see them to begin with.

Case in point: the 1956 DAY THE EARTH STOOD STILL. When Gort picks up the love interest, on the blu-ray you can see tons of wires holding her up. On top of that, there are still a few scenes where you can see the zipper. It would be interesting to see someone take this (and other films like George Pal's WAR OF THE WORLDS) and not so much replace the FX with something more modern, but just get rid of the wires, background mismatches with the set, bluescreen issues, etc.