http://www.steinschneider.com/props/star_wars/darth_vader_reveal/
These remain some of the best pics out there for RotJ reveal reference pics. There have been some individual other shots that have show certain details better, but if you want one source for a good reference this is it. It's what I have been using for my reveal project with only a few other sources to get some of the finer details.
Oh, and if you go to the parent directory there are also great ref pics for other SW stuff, including Vader's RotJ saber.
GB