Here's a comparison with the tour ROTJ I was talking about.
Here's the one I was thinking of, and they don't appear to be a perfect match. The dome on the right looks like it still has a bit of ESB influence to it.
The masks look interesting though. The one on the left has its right tubes towards the camera, and the first 1.5" or so appear to have a darkening effect hints at repair tape like the one on the right. However, when comparing blurry images, you can never state thing as "proof", "evidence" or "fact" and have to allow for other explanations. In this case, we cannot quickly conclude that the darkening is due to a physical change of surface (e.g. tape) rather than reflecting off a dark surface, or a change in lighting.
Edit: the deformation on the helmet on the right by the lower tube - that turns out to be the elastic band.
Ah well... it was fun doing the comp!