All you need is 2cv shafts, a brass-rubbing of the flanges, and a friend with a lathe, right...? Remind me where you work and what you do? You could have the world's finest adapters - so long as they don't go near volcanic ash...

A milling machine with a dividing head will make life a lot easier too, although theoretically you could mark the holes out by hand and drill them in a pillar drill. If only there was some way a machine could do it automatically, but that would be almost too easy.