Got this figured out. The large transistor in position Q411 was fried and took part of the board with it. Was able to locate an exact replacement on eBay, solder it in and it’s back in biz.
The board was so baked that the middle hole for the center pin just snapped off when I tried to install the new one. I figured out what that pin is supposed to connect with and ran a bypass with a heavier-gauge automotive wire (because of the heat). Not pretty but it works.
Also, the original transistor wasn’t even soldered in anymore. It fell right out after I unscrewed it from the heat sink. I’ve never seen that before.
Anyway, instead of it being a 250 pound boat anchor it's back in my game room. Most excellent!!
I can't see a way to load images for all to see from my computer, but if anyone is interested, PM me and I'll send photos of my work.