Ok, well I biased the output tube to about 75% at idle and I wasn't quite happy with the output volume so I started experimenting. I plugged in hundreds of different combinations trying to figure out the right one for the sound I was going for. I didn't really look at the bias graphs, I just went by what my ear liked. I ended up raising the plate resistor on the final preamp so that it would send more signal on to the output. At the same time, I lowered the plate on the first stage be cause it was driving the 12au6 into full distortion by about half way through the potentiometer travel. Of course I also experimented with bias resistors, coupling capacitors, bypass caps, etc. In the end I think it came out sounding amazing! It is dead quiet when cranked full volume and loud enough to be uncomfortable when you play.
I went with two gain/volume pots, one after each of the preamp stages. It does nice clean sounds with the gain turned down on the first stage. It also does really nice crunchy overdrive with the gain maxed out. The second pot acts as a master volume. It allows me to drive the second stage (12au6) into distortion without blasting the output at full. The overdrive distortion tone suffers a little when the master volume is turned down, but will allow me to play without blasting the kids out of bed every time I want to dial in some crunch. As far as tone is concerned, the only thing I wish it did better is the transitional breakup distortion. Clean sounds good and crunch sounds good, but the mid gain half clean half dirty blues tone can sound a little staticky. I could probably do more if I were to build a tone stack, but I don't think I'm going to do that on this build.
Does oscillation hurt the tubes or other components? Sometimes when both the pots are maxed, the output will lightly oscillate. If I scooch the master volume (or the first gain stage for that matter) off the top rung just a hair it goes away. I actually don't mind it. It has a dirty tremolo effect that sounds nice on some single note picking.
In the end I am really happy with the way this turned out. I have attached a copy of the full schematic. Feel free to point out errors or areas I can improve. Thanks for all your help.
Edit- I am leaving this morning for a family Christmas trip, but when I get back I will finish assembling the chassis in the enclosure and I will do some proper recording in the studio to give you all some sound samples.