Well, this is when I've attached the mask to the goggles. I just srewed it on, as you can see below.
Well, not here, but a bit further. The mask still needs some sanding.
...But it is starting to look nice...
The white line on the top, next to the mask is where I nearly srewed this up, literally. The srew I used split the mdf frame, and I had to use liberal amounts of glue, PVA, epoxy and cyanoacrylate to hold it in..
Here you can see a bit more of the insides, I used small nails to further strenghten the joins where I could not, for fear of splitting more, use screws.