[Mondial]

In the meantime, you could replace the 80 rectifier with an 83V, which has lower internal voltage drop and will raise the B+. The 83V is pin for pin compatible as a plug in replacement and draws the same 2 Amp filament current. The main difference is the heater-cathode construction and closer electrode spacing.

The other possibilities are to wire a 4 pin tube base with silicon diodes and increase the first filter cap to give an additonal few volts over what the 83V would provide.