[ARC5] C-744/ARC-5 usage?

[Ian Wilson]

A C-744/ARC-5 control unit followed me home from
the swap meet today. I can find this in AN 16-30ARC5-2,
but it doesn't explain how it would be mounted in practice.

The rear of this small box has an 8-pin male connector
and a splined "spinner" shaft for the tuning control. This
needs a male-male flexible coupling to tune the receiver.

Does the C-744 plug into a receiver rack, or some other
piece of mating hardware? Was it intended for service
purposes, or something operational?

Thanks for any enlightenment.

73, ian K3IMW