[MrFixr55]

I wonder if the difference is due to the fact that the detector in a 37 is a 27 which has an indirectly heated cathode and much different internal structure than the 26s used in the 1st and 2nd RF as well as the 1st Audio. a 26 is essentially an 01A with a very thick 1.5V heater. the lower voltage, thoration and heavy current likely helps the filament not induce AC Hum into the set. The 26 and 27 as well as the 71A and 80 were developed for the first radios to be designed to run off AC. (RCA's eqrlier radios were DC sets that ran on AC due to the "Socket Power Unit" in the Model 104 speaker putting out 3.3V DC for the UV199s in the radio.)

I say leave the coils and swap the caps. Doesn't the 37 have "binocular" coils as opposed to the concentric ones on the 35?

BTW, Navel jelly does a good job of cleaning up the meal on the old caps, issue is that it takes off any plating that may still be there. Keep it off the insulators and the aluminum though.