Both idea's are possible, but I'm not sure which is the easiest to do. It would seem like the over-running clutch, if one could be had as small as the spline adapter that is currently on my clutch drum, would make for an easier (if welding required) solution.
OTOH, being able to bump-start would be equally nice, so replacing the existing assembly with a manual job would also be a nice adaption, as well as the ability to go BELOW 15mph, which I run into a fair amount of these days. But it would have to have some kind of externally cooled throw-out bearing as the bike will coast literally for miles given good conditions.
Either option requires planning, and machining, and thinking, which I'm hesitant to do simply out of sheer laziness.
