They are push-pull amps using octal tubes as finals and 9-pin miniutures as driver and phase splitter. They appear to be made by a skilled home constructor rather than being commercially produced.
Since we are speculating, I would guess a 12AX7 followed by a 12AU7 with KT88/6550 as outputs. The fact that there are no tubes in them may be indicative of problems. Remove the bottoms and look for any burn marks or bulging capacitors, check all fuses for continuity using a multi tester before bringing the amps up with a variac. Don’t want to let the blue smoke out.