Hello Kiwi Biker community

I would appreciate your expert advice? I own a 2002 GasGas 400FSE (fuel injected headache) These bikes have a reputation of being hard to start from cold (mine included) So I have replaced the battery, checked earth wiring, solenoid and the starter button before I found the culprit, the previous owner had given the starter motor hell, by excessive cranking (a problem for some younger male riders ) the brushes where shot and about to start arcing, but the armature bush and needle bearing are showing excessive wear, allowing it to pole and loose power. I have tried my usual bearing supplier but found it to be a special size like 19 OD x 13.5 ID x 12 W?

Can anyone recommend a NZ source of parts for this two brush left hand rotation Mitsuba 12v starter motor (Model sm-14202 or 14203?)

Many thanks

AMS