First thoughts, take 'em with a grain of salt.

1. As long as you have a source for tubes, you're probably OK. Transformers are next hardest to replace, anything else is a no-brainer by comparison. Complex rotary switches are sometimes hard to replace but it's unlikely they are beyond repair.

2. Having said all that, if the tubes all light up it probably works


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8