Hum is greatly reduced. Buzz is my game. Yes, even with no input... when I'm back at it I'll update more, but from memory, when tone is dimed, buzz is reduced.. when I back off of tone, buzz is back.

This is class A, so some noise is ok. There is just too much.

It's almost 100% due to dc voltage entering into the signal.

Where is the question. It is likely somewhere in the preamp stage.

No isolation transformer... so full wall voltage across the tube heaters. So there's that.

Biggest suspect IMHO is the power switch being connected to the back of the volume pot.

Tests tests and more tests.