Aerostar alternator

1987 Aerostar charging light lit and voltmeter low, I removed alternator, brushes seem worn but should still take contact. Regulator seems to be integrated with brush unit.

Any typical failures known in the charging circuit ? Regulator, rectifier, contacts, something else ?

There seems to be lots of different types of alternators available online, how to identify which make/model(current amps) et.c. ?

br Vesku