you can probably get new brushes and polish the armature to keep for a spare.
I had the starter on Rauzer II rebuilt a couple years ago at an automotive starter/alternator shop and the cost was about $50 I think! Has been working great since.
Question: how many follow the operator manual and put the throttle at 'full' when starting cold? I used to put it half way and crank and crank until it finally caught. Then I read the manual and now set at full throttle when cold and it usually starts within a second or two of cranking. fyi fwiw
