Smokin Hot Alternator

Hi guys, Im in the early stages of getting my 74 bay back up n running, over the weekend while I was stripping the interior, my buddy hooked up the battery backwards allowing "the smoke to escape from the alternator". Any ideas what has been burnt and do I need to remove the alternator to replace diodes etc or can I do this insitu.
Gus

is it an alternator?

Type 1 motor or type 4?

My guess is the internal regulator is stuffed on an alternator and will need to be removed to be repaired

Type 4

Diodes are probably toast. You will have to remove the alternator and strip it down.