A blog called paper juke has a pepakura file for the mask. If you are looking for some thing else I would start with reference pictures of which google or bing are full of.
Pepmaster also added a Death Mask to the pep gallery. I recently put it together and it didn't turn out to bad unfortunately its to cold to resin so I cant finish it.
As for sculpting you really can't get away from it unless you go the papercraft rout. What material you use depends on the tools at hand. Clay is probly the simplest to dive in to as you can use a lot of house hold items for basic tools at the out set.
If you have the $ for some hotwire tools styrofoam/constuction foam is not a hard matirial to work with either. Care needs to be taken in the finishing part as some paints and finishes will desolve the foam without proper sealing.
Never be afraid to dive in. You've never sculpted before, so what. Swing by the craft store, grab a bit of clay and give it a whack. There are a lot of reference photos on google and a lot of sculpting techniques can be found on youtube. Same goes for pepakura. From cutting ot the pieces to hardening the mask for use have videos out there that are very helpfull.
Pepmaster also added a Death Mask to the pep gallery. I recently put it together and it didn't turn out to bad unfortunately its to cold to resin so I cant finish it.
When you tried to open this .PDO were you asked for a password? I'm using Pepakura Designer 3 and I'm being prompted for a password but I thought the file was free. Thx