It was out by 0.6mm, too far over to the brake, so only needed 0.9mm, rather than the 1.5mm I specified. I think I'll live with that, as the MZ is likely not perfect anyway, and I'm hardly doing MotoGP with it!
If repeating, 0.9mm isn't much, so you could run the sprocket slightly out and centre the wheel I think?
Anyway, new XT sprocket to retain skorp gearing (15/43), and the old XT disk should clean up.
It's off getting the (old!!) tyres put on, which will do for an MOT till I decide what to do with it longer term...