*** Many thanks to Skunkie*** who did the heavy lifting.
While waiting for the parts to "fix" an A-12 bought at Christmas I did the digging and found out a 6V6 was a good holding option. So, I snagged a pair of JJ 6V6s tubes. I actually liked the sound of the 6V6 tubes and thought they had potential. I bought an A-10, just to run the 6V6s tubes, and when the parts arrived I modded the A-10.
I did all the mods excepting: I left the 500ohm resistor and the 220uf capacitor alone on the power tube, I didn't tweak the power supply, nor did I change the rectifier tube. I changed the coupling capacitor (same value, just a bit better quality) set the feedback resistance at 620K (rather than 820K), and threw a pair of Russian 6AX7's at it.
I might as well do this here:
https://www.jj-electronic.com/en/6v6s
It sounds pretty damn good to me and think it a good economy option (cheaper tubes, less parts) at the cost of a watt a side.
The real bonus is heat, or almost total lack of it.............. the power transformer is "slightly warm", not hot, and believe it or not, cooler than the output transformers. The 6V6 tubes seem to have a better frequency range than a KT77.