Apparantly Ian gained some weight mainly between AotC and ROTS. And it doesn't really matter that he looks different in ROTS. We don't se him again for nearly 25 years. The ESB hologram is problematic though. Some work can be done on it, but I imagine that getting to look like he does in ROTJ is very difficult. That's why I mentioned that he could be "hidden" with only parts of his face visible. I'm no fx artist by any means, but it sounds like that would be less work for ady (forgive me if this is an incorrect statement) and would also work to give it scary feel and mysterious feel as well as to preserve the "face reveal" to ROTJ. Of course in light with the PT, it would be more of a re-introduction. But that works fine too IMO.

Lucas changed some things way before 97, like Beru's voice and apparantly some other things as well I've heard. It would have been nice if he re-did the hologram already back in 1983 so that he could have looked exactly the same. But nothing can be done about that now anyway. Just a bit of a shame, is all.