I SHOULD, but I don't.
Also, those old renders from Descent2.com always rubbed me the wrong way. The textures and shading look weird, and the robots don't seem right floating in space.
I would take screenshots of each robot instead. The best way to do that is use the developer version of D1x/D2x, you can find the link in this thread here:
http://www.dxx-rebirth.com/frm/index.ph ... 874.0.html
That comes with a model viewer, which should give you good fine-angled shots of each robot. Just be careful not to play your saves, the dev. version can be a little wonky! I can't help you with D3, though.