[RodB]

You are kind of on the right path. You can touch the grid cap of the Detector/Oscillator 36 tube. I'm expecting a response of the radio sounding normal. Doing this bypasses the antenna transformer and the volume control. If you get the same response by touching the center terminal of the volume control then the antenna transformer is OK. If not, one of the coils of the transformer is open and you can use a meter to test for that. If the transformer is fine then the problem is with the volume control. You can either open it and clean it with Deoxit F5 or you can spray the cleaner into the control and work the shaft back and forth.