A few years back I had a Bosch alternator from a B20 that had the guts out of a Commodore alternator in it. The front casing was Volvo/Bosch and the rest was from a VN commodore which, I think, made it a 65 or 85 Amp alternator. It looked original, all bolted up without modification and the only wiring difference was the connector on the back for the low tension wires was different. I think it had a plastic plug rather than a spade terminal.
The other difference was an internal voltage regulator, which is a good improvement on the remote one.
The alternator in question is long gone so I cannot check it though it looked like a great solution. Your local auto elec can probably help you here. They would also be able to rebuild it as they are fairly simple to rebuild, so long as no major problems.
