Hey Tandhem, this sounds like a pretty promising idea. Thanks for the great tutorial. I have pepped a lot of ODST pieces, including my Rookie helmet, and I think I'll consider using this method.
I'd feel a lot more confident with the new method (I'm just scared I'd ruin the whole helmet) if you could possibly post a video of you using this method on a piece, showing how you a) mix the Rondo, which I'm kind of new to, :coolapply the Rondo and the matting to the Pep piece, and (possibly) c) a bit of sanding so we can see how it looks sanding through the paper layer. And explaining everything like you were talking to a four-year-old.
I know you already typed a big post, but some people (like me) just have to visually see it to understand it better. I'm mostly curious about mixing the Rondo.
Anyway, it looks like a great method and I can't wait to see the finished piece! Are you supposed to do a final outer coat of resin once you finish sanding, so the edges aren't papery, etc? Sorry if that's a stupid question, but it seems like it would make a nice smooth finish.