I assume you are talking about the ARC 7491 loop control? At https://aafradio.org/garajmahal/ARC-5_loop_control_knobs.html you may find some possible ideas. Having said that, for all the ARC designed receivers that have loop controls, I must admit that I have never seen a photo of one any being used in a WWII aircraft. But for today's command set enthusiasts, of course! Pretty neat capability!

- Mike KC4TOS

On 12/12/2021 9:35 AM, MARK DORNEY via ARC5 wrote:

I’m going to try to make the antenna control for the R-23-A/ARC-5 from scratch using junk parts. I’ll send pictures when completed. 

Mark D. 
WW2RDO