SSD
I had a few thoughts about the "wellie on a rope" idea. I don't like it too much - too many possibilities to get the rope caught in the blade or the wellie stuck on blade for a couple of rotations, pulling you in very quickly towards the rotating blades (not to mention fouling your expensive prop!). I know that some Yak owners have quite successfully hand swung their engines into action having been caught out with zero air pressure for one reason or another. At least using a correct technique one ought to be able to swing it safely (you would need to ensure it was very securely chocked as no air pressure to start also means no brakes). With the 52, the prop stands perpendicular to the ground - helps hand swinging. With the Yak 50, hand swinging would require even more care as the angle that the prop stands to the ground (being a tailwheel) means that it is closer to the body at the bottom of its arc than at the top...
Just thoughts (to get the Yak thread back to the top of Private Flying!)
Cheers