WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
connect both systems in parallel, use half the cathode resistor value which is in now and double the cathode bypass cap. Connect the output coupling cap to the anodes and a plate resistor 5k/10W from anodes to B+.
Alternatively you can try just single systems: Disconnect the upper system in the SRPP stack, or better ground all unused elements. Leave the cathode R and C and use a 10k plate load resistor.
I forgot to add: you should then also change the bias voltage of the heater. As a first try you can simply reference the heater to ground. Or change the voltage divider which elevates the heater to values which will bring it ti about +25V.
No that will not work. The 22uF would short out the output signal.
Maybe you should read up some basics before you attempt such mods.
As has been suggested on this board, Morgan Jones books are brilliant.