ASR 33 buzzing

So I've been having fun going over this 33, trying to follow the schematics I've found. Still like visiting an alien world but, I did manage to get the keyboard functioning properly and fixed a couple of broken keys, so that's progress at least. I've tested the caps and they seem to come back okay, as do resistors. I've looked around for any stray/frayed wires. I figure if the thing was working before it left Toronto something might have gotten loose or broken. There were also three machine screws installed for transport, I don't think they would have accidentally touched anything they shouldn't, but who knows. Anyway I'm looking again at the three fuses up top .. 1/2, 3/8 and 8a. They're intact but they look a bit rusty inside: https://drive.google.com/drive/folders/0B4pq0-BHd2x6bjY3MTRZbGRCQmM I don't know how much rust affects these fuses - I would have assumed they'd just blow if they were compromised. But I'll order some new ones in case.