Okay, here's where I'm going to need some info from the more experienced folks.
I had a look at the TV chassis and schematic to double check that it matches before I go ordering parts and find out there's a major discrepancy
There's one thing I found that is off - in the schematic, V8 is marked as a 6W6 and has the first audio stage coming in on pin 5. However, in the chassis, this is wired to pin 6 of the socket, and I found not a 6W6, but a 6V6 instead.
A quick search says they're pin-compatible but not exactly interchangeable, any thoughts on this?