71 Demon Radio Removal

I know of some hardware that was added in 1968 for their dumb wheel radio. However I don't know if all this was deleted from all models/builds when they switched back to the knob radio. My pizz poor memory is suggesting a knob type radio with the added support plate(s) on it. That's the only reason I would respond to mention here. Soooo. I would remove the ash tray support and feel around between the radio and wiper switch. I just might find what is called a keyhole stud with a nut there ( about 3/4 inch from the radio chassis ). And if there is one found on the left side, there could very well be one on the right side also. I just don't know.
Best advise is the factory service manual correct for your 71 model rally dash.