[thinktreasure]

Steve do you have a signal generator? If so you could try putting a 470kc mod. signal in the IF stage then det./ocs stage  moving backwards toward the antenna connection to see where you lose it.
 I assume you have checked all the tubes and I would also clean the band switch very well.
Did you have an antenna hooked up? Just throwing out some ideas you could try. I'm by far no expert on these radios.
There are guys and at least one gal ,Brenda ,on here that probably have forgot more than I will ever know about  this hobby.
Good luck

I found something else on this radio
It varies from the 2 schematics I found online.

In the center of the chassis there is an additional bakelite condenser this is not shown on the chassis layout or in the parts list.
Does anyone know if there is a later or earlier version of the 37-611 that shows this change?