You're probably right about keeping this thread sacred. Well if there's any interest, please go to this thread, where you'll see a lot of information on tri-colour cameras (there's about as many ways to refer to them as there are optical paths!... argh!)
I'm not outfitted to build any kind of camera, unless it's built of balsa wood or popsicle sticks, or something. I'm hoping that the "brain-trust" exemplified in this thread might be able to come up with some clever ideas if prompted.
Last thought; the bounce back problem is actually a problem of refraction. Since there is thickness to the mirrors, and the light enters them at angles, some of the light will be separated by a distance equal to the thickness of the glass. Or at least, something to that effect...