Rattletrap52,
I do not have any good photos of the dash but here is a diagram of the recirculating heater system that comes from the 1954 Accessories Installation Manual.
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http://home.nycap.rr.com/lederman/images/heater.jpg[/img]
The heater switch for the Chevrolet Recirculating Heater and the deluxe Air-Flow Heater were mounted in about the same location, under the dash to the left of the steering wheel.
By the way, I think I was wrong in my posting above regarding a heater being standard equipment. The 1954 Truck Data Book does not show any heater as standard equipment. Both heaters were dealer-installed accessories.
Tim