Thanks, of course I don't need the clamp on part, but if the roller fits that should do, looks plastic though or is it PTFE ?
Didn't think of getting one made, I know a man that just might be able to do that from a slab of Aluminium. He builds up old vintage cars making his own parts for them, so that should be a do doddle. Just the bushing in the middle where it fastens may be harder to make/fit.
Though for the price of that roller, I can could probably sell my M900 front mech and buy a M901 version, lol.