For the Dumble style amps, your schematics have R14 and R16 listed at 3W and 2W respectively. These values seem like way over spec'd to me. Assuming plate current for the 12AX7 should be about 4mA total, and the voltage drop (about 40V) would occur over R14, R16 and R17, none of these resistors should be dissipating more than 1/2 watt per resistor. So we should be able to use 1 watt resistors here.
Am I missing something? Or is that just the way HAD did it?