Tim
"You can see it might have had a decal above the knob? I think I have one knob like that in my collection. (but, no attachment plate)"
Hi Tim, I did clean up the plastic face plate on this switch. I'm looking for a way to rebuild the porcelain covering on the back spring which I assume is the heat sink.
Because my heater motor was seized when I bought the truck I did try the switch after I cleaned it up by hooking up direct to my 6 volt battery and had current flow in both fast and slow positions, also the small 6 volt bulb located inside the white knob does work albeit very dim.
Doyle