Allright, guess number two.
They look like gearboxes. Not for a DT but to reduce the CIMS and FP w/ AndyMark planetary's. The CIMS and AM's look like a PERFECT fit for the solid (ish) plates. Toward the left hand side you can see two large holes and the 4 small screw holes to hold them in place. I definitly smell gear reduction. That is my best guess as of yet. I dunno if I am right... I still don't know what the pretty CNC'ed ones are for. Anywho they look nice and I hope whatever they are made into turns out well.
-Henry