I was surprised to find a new starter motor for sale in the UK, so promptly bought it (probably the only one out there) which arrived today, total cost £136 with free postage.. not too bad.
Soon had it fitted and with fingers crossed I hit the starter button.. thankfully the engine turned over ok and the electrics behaved themselves. Phew! But I cant try and start it yet, as the clutch slave cylinder is off the bike as it's leaking and needs a rebuild kit.
I also need to buy a new Lithium battery which needs to be small enough to fit where the old Ballistic battery went and powerful enough to start the engine. Found what's needed.. made by Anti Gravity, but at £200 it'll have to wait a few weeks.