[mikethedruid]

Another thing has just occurred to me after rereading your posts. You say you bought a 37-620 radio. I take it you mean a complete radio, chassis, case, and SPEAKER. On these radios, the field coil of the speaker forms a filter choke for the B voltage power supply to the tubes. If you have, that is good. Also, from the pictures you posted, I don't see the speaker mounting board. Did that come with the case? If so, did it have the original speaker with it? I am not sure if the speaker used in the table radios was the same diameter as the ones used in the consoles, so the smaller table speaker may not fit the original speaker board. That won't be a huge problem if you are getting a speaker with 620 you bought. You can just make a suitable mounting board from 1/4" plywood, and cover it with the appropriate grill cloth.