In 1952, the deluxe heater used holes under the dash for:
- to the left of the steering column, a control-cable for the defrost flapper in the heater box.
- just to the left of the heater box, a control rod for the heater heat-control valve
- also, to the left of the steering column, for the heater fan-speed control switch (used with both heaters)
The locations are described, and not so clearly shown, here. 
