Well I spent all of last night messing with the back pots and I've gotten it as best as I possibly can with what I currently know.
See here. Greyscale is good, but overall picture is still washed out and everything has this weird bright halo to it. Sharpness still varies quite a bit, I caught these pics when it was on the very low end. Typically it looks good on power on and gets gradually worse. I've found the only way to get a correct contrast image without overbright is to turn every color G2 to its minimum, and user brightness to maximum. But this produces a lot of black crush.
I still believe there is a master G2 somewhere, and it is WAY too high. But I can't find it anywhere, or the focus terminal for that matter, and hoping at this point that someone else will know where they are..