I know myself well enough to know that that's an area I DON'T want to go messing in.
That's all going to have to wait till after the holiday bills, though. What I'm kind of hoping to have happen is have a way that the master vol pull switch can be used to bring a pair of tubes online or offline. This way, the amp can be both a 50W and a 100W amp.
I really should learn how to read those diagrams... I could see how one could make money doing hand made custom built amps for the well heeled. I was talking to the local amp guy, and he said he could see doing one on commission, but that it would require some 2500 to 3000 bucks before he'd be interested.