It's looks to me like it's metal, most likely aluminum. I also have a guess about what those black holes are. I'm thinking that they may be mini fans like the ones you see used to cool the North bridge on a motherboard.
Back on track, I'm looking to build my own Mau5head for Halloween. I'll have my supplies by this Friday and will start construction this weekend. I'll try to document the build as best as I can.
Spidermanc, your mask is awesome. Can't wait to see it completed, and I'm looking forward to reading about all the details about it...dimensions, fabric used, items used for the eyes, etc.