super awesome pep! good job! scoring the paper with a pen is a great idea, and very ingenious, though you do lose the ability to diferentiate which fold is which. but you cant argue with the results! have you tried using two pens, like black for mountain and blue or red for valley, then you can score everything while its flat. for me, i score the fold lines with the back of my knife, i like it because i find that it creates enough of a gat to get really crisp lines with my folds.
Try a search for "Skyrim pepakura". It should bring you all the skyrim related stuff for pepakura. Within that search, you'll find the user with the pep file. I'm pretty sure his name is *z8-0. Try that. I'm pretty sure if you look under my favorites, you should be able to find him. Good luck!
I line everything first with a pen. I mark all the lines that fold one way, fold them, then repeat for the other folds. Since there are only two types of folds, just pick whichever you like first. I usually pick mountain folds first, then use a ruler and a pen, mark the line. It creates a super small crease that helps you fold the line when the time comes.