I
think they use some sort of cheap, tubular copper rivet, similar to these:
http://www.leprevo.co.uk/photos/rivet-65., whatever they actually use,they are pretty use
less, and the leather they use is frankly of shocking quality, given the price they charge for their tools-excellent though they are.
If you want to do a
real job , that will actually protect both you from the axe cutting edge and the edge from damage, as well as pretty much last a liftime, then you need to use these:
http://www.leprevo.co.uk/photos/copper-rivets.html
But if you want to use them, you also need this:
http://www.leprevo.co.uk/photos/copper-rivet-tool.htm
Then of course you're going to need some decent hide, ideally oak or at least "vegetable" tanned and at least 3.5mm thick.
I'd suggest just simply copying the original mask, using it as a template. Don't forget to add a decent welt between the two sides of the mask and see where you end up.
Something like this;
Once you get the measure of these, it's a doddle but it's one of the leather working skills that takes time and patience to master. I practiced on scrap leather till I had it just so.
I must have gone through at least 15-20 rivets before mastering the skills required.
Might not sound much but these aren't exactly cheap and there's a
bit more to it, than just sticking the rivet through a punched hole, putting the washer on and battering away with a hammer
good luck
Steve