Motorized display Osprey

Maybe phone vibration motors

Pretty small motors that run on up to 3.7 volts can be found in small RC airplanes now, look at an R/C store in the repair parts for things like the Vapor Lite sold by Horizon Hobbies.

https://www.horizonhobby.com/17-000kv-6mm-coreless-motor-p-eflum6809

I'd be tempted to put the motor (s) in the fuselage and use shatfs and gears.

That would be nice but asking for trouble. I could get NASA to solder the wires to the world's finest mini motors, and they'd still find a way to stop working once installed and sealed in. Murphy's Law. 

This reminds me of the greast 1/72 counter rotating prop challenge.

There is a mind blowing motorized Lego Osprey on the web.

There was an article in the December 2006 issue of FSM where someone did just that with a 1/72 scale Italeri Osprey kit, so getting motors to fit a 1/48th scale kit shouldn't be a problem.

The author said he obtained the motors from battery powered toy monster trucks which cost $1 each, but didn't indicate where he got them from. He also replaced the plastic prop shafts with brass tube, running in a larger diameter brass tube mounted in the nacelles to avoid the plastic shafts melting.