I don't believe it is a Bosch; it was a free one, rebuilt by someone in the past. It was sitting on a good engine for a number of years. No doubt I killed one of the diodes when I yanked off the ground to stop the 'new' starter from continuing to crank when the engine had already started.

The regulator/brushes may be fine; my question is are the diodes on the alternator, or on the regulator? All I know is I have a bad diode; replacing the regulator may be unnecessary.