My first though was, what bevel gear are you using. More importantly have you found one you plan to use or is it still theoretical.
Having experimented with this kind of space saving, we eventually came to the concussion that the most efficient method is to flip the motors around. 971 did this in '12 and '13 and our ball shifting gearbox copied that this year. (The most similar example may be Texas torque's gearbox from last year, I believe it was a vex ball shifter with custom plates so the motors hung over the wheels)
That said, I really like this and the out of the box thinking behind it. It reminds me of the things I thought about when planning 192's '12 and '13 gearboxes. I've worked with right angle drives, the construction technics you seem to be using and bevel gears so let me know if you have any questions.
