I don't use it much, every once in a while it's handy.
It use to be erratic about starting and now it mostly won't.
Symptoms: it runs only at the medium speed, and starts only after tapping on the case gently with a rubber hammer. When running changing the speed control kills it immediately.
A couple years back I thought I'd clean and lube it, but couldn't easily get it apart, and stuck it in the healing pile. But recently I read that worn brushes stick, and the hammer tap frees them. I tried that and it seems to work.
So are brushes available, and is disassembly worth the effort? It doesn't look easy. These weren't designed for maintenance, I think they are intended as consumables.