Bob, The tube that's in there currently is a 12AX7 (actually an ECC83). I have a bunch of 12AX7s and ECC83s lying around. What's your idea for going lower gain? Reduce heat in the preamp stage? Get more grunge?
I was wrong when I said there was hot melt glue on the resistors, it appears to be silicon. I should be able to pick up some silicon or epoxy at the grocery store tomorrow to complete the project. Right now the amp is back together and works like a charm. The hardest part of the project was getting 5 tiny indicator lights back into their holes in the faceplate during reassembly. What a PITA.
John, my heart felt thanks to you for walking me through this process. I was afraid it would be another year before I could use my favorite amp, but now I can use it for a gig Friday. Just in case I'll bring the Ampeg PF-500 I bought this summer on the way home from the repair center in Houston after not quite believing the repairman who said my amp was "good as new, trust me".
I'm feeling all self confident now, maybe tomorrow I'll open up the compressor I have that has had a bad output transformer for the last 5 years.