I've re-uploaded the zip file of the biceps with the size testers that were unfolded by Ral Partha, and have put a new version of the HD bicep up as well. I found two problems with the old file.
There was one part that was supposed to be flat, but had an unnecessary fold, and I've split the large support into two pieces so it can fit on the pages. I'll unfold it today. I'm almost done with the left bicep.
You can still use the unfolding that Ral Partha if you want it now, but it'll have those problems.