Having had bad experience with some aftermarket SR28X starters, I bought a "Bosch Premium" branded rebuild.

My old starters have Bosch markings stamped in the black metal motor housing. (Both the very old large type that came with the 82, 83, and the later smaller, permanent magnet gear reduction starters)
The rebuild I just bought has no Bosch markings. What have others found on their rebuilt starters?
Do rebuilders generally reject non-Bosch parts, or reuse any cores they get?
I would mostly concerned with the copper windings in the rotor of the PM motor. That's what has been bad on the aftermarket starters I tried.

Martin (and 82 Westy 1.9TD in Canada, 85 Gas in Europe)