This is really cool!! Thanks or sharing!

Man, this guy have some very rare stuff on his harddrive.
Hope for some more stuff.
May we can invite him to our board to share some more stuff like this?

Really cool videos there! :D

amazing

It's an illusion. If you have lenses that don't have strong ambient colors but look that way on screen they mimic a transparency. Put your masks on grey carpet or any darkish sober tones and they look grey but are not, if you pick the mask up and look at the lenses from the inside it should take on some tonal values of transparency from even a colored wall etc to show both a clearness and the colour that's behind the lense.. If you don't get the same effect, the lenses are not correct in colour.
That's why many think the elstree mask had grey lenses, even Prowse did for a short time in his book I did the same tests, producing the same results.
I always find the subject facsinating with these type of aspects. The lenses are not grey or red, they are a tea stained color which is best described as Amber but the depth of the colour isn't strong as some think on thoses ANH lenses which mimic certain lighting and transparency, even from the hues of Powse's face. The similar but differing perceptions found on the later stunt masks in the trilogy.

Thanks Dave for pointing out this incredible footage. In many ways it is an answer to my prayers. There's so much going on here. But the most important thing to me at least is seeing the back, bottom and at least part of the inside of the mask. There's some questions I've had for around nine years that I think I might finally be able to answer with this. Really an amazing amazing find and very exciting to see.

Yes with the tabs it was clear from the footage we knew before from this that the helmet just had to be pushed down a bit to "snap" the tabs into place.