=>Any tool service place or washing machine repairers will have brushes, =>just a case of file to fit! =>
=>Niel.
IMO it's a little more complicated. IIRC, the X03/4 mounted the brush to a brass arm via a small protrusion on the back of the brush. That's a little tricky to file IMO. One could replace those brass arms with phosphor bronze "brushes." Wear better than brass, and with proper electronic cleaner-lube applied should run quite smoothly. Easy replace when they wear out, too.
However, my preference would be to replace the motor with a newer type. I've tried cobbling upm repaiors to old motros, and it just ain't worth the hassle. The old motors are simply not as good as the new ones. The older I get, the less time I want to spend on fixing stuff that wasn't that good to begin with.
HTH&GL