The only option for the mask is THS's mask.RubberGorilla doesn't offer the mask anymore
my plan was/is to cast it in resin - but what would be the most desireable material?
Looking forward to seeing what you come up with mate. You did a really good jod on your Ledger bust.
Are you sure Smooth-cast 320 won't be too rigid and maybe a bit brittle for this job? But then again if you've already got it to hand go for it.
I think a high shore urethane would be the ideal stuff to cast in, but it can be a bit pricey (well over here at least).