Here we have a photo of a "Tomcat" amplifier:

And here is a photo of the later unit, in this case an AP-737, I think:

By the way, Wayne, don't let the occasional goof get you down. It was a lot easier to learn about this stuff forty years ago, when none of it had any commercial value, and one could wantonly tear stuff apart without the pangs of remorse.
An RCA "Red Book" should be a great help in sorting out the internal components of these machines. I will check to see whether I have a spare copy of Vol. 1 (1923-37). If I do, and I can find it you are welcome to have it.
We who live "up north" tend not to be cognisant of the damage that can be done by wood boring insects. I do hope that you are able to fix your 12-15.