[RodB]

Power supply filter caps for the 80 rectifier can be increased considerably when not using a filter choke. If you experiment with 22mfd caps and temporarily connect them across the installed ones you might be able to cut the hum. Indeed, this is the circuit to use until the correct choke comes along. Buying a new choke will be very expensive(copper). I will check my stash for one that is close. If the rectifier tube was one with a cathode the tube specs would tell you the maximum capacitance for the input filter cap. If you have a voltage chart you can also experiment with the 200 ohm resistor to get the correct B+.

Edit: I don't have the choke you need.