RE: 1/5 scale Bell P-39 Aircobra...
Darrell,
I think you may be onto something there. I have a set of the Robart T-6 gear from a Midwest Texan I am restoring, and a set of Pepino's plans, so I took some shots that may help you out. Looks like you will need slightly longer struts that a yoke for larger wheels, and a set of 85degree blocks on the gear, but other wise it should work. The wont be swept quite to the scale location when retracted, but will be pretty darn close. Also, since the legs are positioned away from the air cylinder when retracted, you can the have struts made with scale scissor location.
Feel free to use these pics as needed, and send to Robart if you want.
Terry