RE: Custom landing gear engineering question
Check out e-flites electronic retracts. You can probably use the nose gear retract. It's one piece - servo built in. You can either cover the landing gear wire with Robart strut covers, or get an aftermarket strut to keep the scale appearance.
I was thinking of ways to create what you asked for, but my solutions were involving screw drives or bell cranks, taking up a lot of money or space.
I agree that it looks fairly easy to make room in the belly for a folding gear. I also think it would be more robust than an axial-motion device.