I've put in new caps, ceramic sockets, quad cap and rewired most of it.
When I power it up it makes a hum noise a few times, as though you were touching the center conductor of the audio input plug with your finger. It does this 3 or 4 times for a fraction of a second, then it goes away and never does it again.
The choke looks like it has experienced some heat at some point in it's life as the chassis around it's mounting position is brownish. It still measures the correct amount of ohms. What are the symptoms of a bad choke?