[Reece]

Do you have another first audio and audio output tube? If so, try them one at a time.

Just replace that capacitor and forget the wire coil on it, or do as suggested and put the new cap inside the old coil.

Don't replace all the resistors. Try this: get a can of computer keyboard cleaning "air." Turn the chassis over and turn on the radio. Wait for the sound to go bad.

Turn the can of "air" upside down and use the extension tube. Upside down it will spray cold liquid. Drip some on resistors in the audio and power supply section one by one, get them cold again, see if doing so on a particular one makes the sound come back, then that's the bad resistor.