That forum closed down before 3D models really became a thing. Only at the very end, when member participation was almost gone saw the start of anything 3D model or scan related, but nothing came of it. Btw: how can you access posts on EndoBuilders? The site is gone.
I replied to your pm regarding a good arm model.
Thanks for your comments, but I sadly do not have the skills to 3D model the hands, nor the rest of the endoskeleton, but we may show something soon though.
Regarding files... the free ones are hard to find good ones, but some of the pay ones are pretty good.
EDIT: Found this one, which seems decent, but it's lacking detail on the shroud near the elbow, and I don't know how accurate it is - he uploaded it as an .stl file though, so you would probably need Meshmixer to split it apart (Further EDIT: it is 1 single file, so it cannot be split... so this one really doesn't work. I'll alert the uploader of the issue):
My attempt at an accurate movable terminator hand. I made this in Sketch up and models must be imported in inches to be the correct size. They are named as close to actual anatomy as I can figure to help in assembly. Also 1 is thumb 2 index ect.. 1/8 in rod cut to 5/8 in pieces will hold most of...
sketchfab.com
Incidentally I also found this game rip Genisys endo model:
VIP FREE - Terminator ((T-800) YES VIP - Download Free 3D model by darenr23567
sketchfab.com