[rfeenstra]

I recently did a 37-116, have another one and a 38-116 in the que. You are correct. The mask needs to rotate freely on the hub else when changing the band switch, the tuner dial will want to turn as well. I did not have the problem of binding or shrinkage that you seem to be having. I checked the 2 in line and I can see that there is a bit of friction between the mask and the hub on both radios. Not enough for the band switch to actually turn the dial but you can see that it is trying. So, I assume I'll have to sand the inside of the mask to eliminate the friction.

I had no trouble removing the spacer on my 37-116. Don't know what I'll run into on the other 2. I'm not sure of the composition of the metal, but if it is something akin to pot metal, it could be expanding a bit.