Radio Control Box BC-938-A as used in SCR274 System

This is a WWII or post war era BC-938A Radio Control box as used in aircraft of the US military with the SCR274 communication system.  The box was installed in the aircraft cockpit and connected to the aircraft's centrally-installed radio transmitters.  It is very similar to the BC-602 box used with the SCR-522 Command Radio System. When depressed, the buttons configured the communication system as desired by the operator (pilot or co-pilot). Buttons A,B,C,D applied to specific communication channels, which when depressed, select the channel desired to transmit and receive. The OFF button disconnected the channels. The purpose of buttons 1 and 2 are unknown. The TONE-CW-VOICE switch selected the type of transmission desired. In the VOICE position, voice is transmitted when the push-to-talk button on the control wheel is pressed. In the CW position, a continuous wave, or un-modulated signal, will be transmitted. In the TONE position, a modulated tone signal is transmitted. When the swit