This is on a 79 ramcharger.To the left of the ashtray about one inch there is a cleanly stamped hole approx 1 1/4" diameter with a "keyway" for lack of a better description hanging down into the hole approximately 1/8" of an inch. What the heck was there? A hand throttle? I try to put up a picture later.

Bought a 79 ramcharger brand new, and the ONLY interior light was a license plate light-looking thing in that spot you describe.

Thanks man.