Ive been chewing this over and here is the mount I designed
it is a flat mending strip attached to the bike, then a strap gate henge attached to that on one side, then an "L" bracket as a lift handle.
http://i25.tinypic.com/hun1c1.jpg. I might have to add a platform onto the henge to hold the motor.
I think it has a square box on the end of the clutch. I can imagine fitting a nut in there and drilling a hole through the housing and the nut for a pin. then having three nuts welded together to make a holder for the drive wheel.
A simple screen door type spring to keep the tension on the tire.
That should do it. At least I think so. With a little luck it will be the ultimate simple inexpensive motor bike.
elegant in it's simplicity...