Bill,
I think there is a photo or diagram of a Vega with a H-M style JR somewhere in one of the older JRA-newsletter.
Actually, I have been thinking that if I get dumb enough to start another JR conversion project, and if I am not (at least) smart enough to downsize into a big dinghy, I could well end up with a Vega, myself. There are plenty of them around here, and even the good ones are not expensive.
One thing which one must do if fitting a JR, and that is to construct a new rudder and fit it on the transom. This is because the original rudder struggle with coping even with the Bermuda rig, in a quartering sea. With a sloop JR, the new rudder is simply a must. In case your boat has been modified to outboard engine, I suggest the new rudder is moved, say, 30cm to starboard, and with the outboard moved 20cm to port. This way they should ‘cooperate’ well.
With a powerful JR and an equally powerful rudder, the converted Vega would become both easier to handle, and faster on all legs than the original.
Arne