Ken, if you happen to recall the poorer quality construction Command Set LF rec, i would like to know which. I don't collect Command Sets and have only a couple transmitters, and haven't examined examples. 

I think the dial-less rec must be the postwar 'ARC Type 12', is that right ?  Years back i was offered some Type 12 VHF recs that had the freq "dial" ( for lack of more appropriate term which i cannot think of ) installed on the front. Pretty neat job.

So i am wondering about the relative "build quality" among the 3 versions of the LF rec, the SCR-274N, the ARC-5, and the Type 12. It's easy for me to believe the Type 12 is the "best" as it was produced in a more relaxed time, but i admit, that's just my idea.

At one time i thought the AM BC band Type 12, with the 0.5 - 1.5 dial installed on front, like the VHF  modified recs i once

 saw, would be pretty neat, but i have more than enough projects already, than to pursue this.

-Hue Miller