So a few notes as of now: I started out using the tacky craft glue, it holds well and stays plastic enough to get parts into position before hardening. I recently switched to a super glue gel pen. I can use less glue and it quickly adheres and I dont have to worry about pulling it out of position; I think I will be staying with the super glue from here on out.
On folding: my very first attempts at Pep were actually on a test prop pistol (actually an M6R Reverse throwing Pistol from the Halo CE Cursed Mod). On that, I was just folding on the lines by hand, and it shows; the lines are not very accurate or crisp. My next piece, one of the hand plates, I used a clay-molding tool as what I now now as a bone folder. Unfortunately, the tool was so thick, that it was hard to accurately place scores as well as being rather soft plastic that I had to keep sharpening to the point that it had changed shape. From here on out, I am using the back of my X-acto knife to score the paper and it is working great.