Originally Posted by Brad Allen
Well you have a bit of a conglomeration then, the Norco valve is not used with the Recirculating heater. A lot can happen in 67 years, motor failure, valve failure who knows? A full Air-Flow installation looks like this from the cab.
https://www.flickr.com/photos/advance-design_parts_co/17058542759/in/album-72157651718017649/
The reason you do not have the plate is it was most likely an Air-Flow install. This is the picture of the two block-off plates provided with the Recirculating heater.
https://www.flickr.com/photos/advance-design_parts_co/15838946822/in/album-72157631868452754/

Thanks Brad! So in that photo there's the side panel block-off plate. My truck has that block-off plate installed, however in the bins of parts that came with the truck was the vented plate. Still, no round firewall cover plate. I tested the fan motor but haven't tested water flow in the heater core. The switch and the fan work great (especially with a 12v battery) and I have a 12-6v transformer so i could just put it back in as it was, but would really want a cover plate on there so it's not so ugly.