What are these supposed to control?

[willincalgary]

I am in the process of tracking down things that rattle on the highway and found two controls (no longer functional) that I have no idea what they do/did. I've always known of their existence but never really looked into their function. In the photo they are the thing attached to the hand throttle and the knob beside the choke.
The first knob, attached to the side of the hand throttle has several "stop" positions and has two electrical connections on the back. Strikes me as a potentiometer of some sort.
The second knob, beside the choke, has "Fast - Slow" written on it and is intended to turn. It goes through the firewall and connects to nothing at this point.
The vehicle is a '59 Series II petrol.
Any help would be appreciated.

[HybridIIA]

Both of those are previous owner additions and not original to the truck.

[o2batsea]

Actually, the control next to the choke IS original, although optional. It's to turn on and adjust the speed of the Smith's heater.
The other switch is probably an add on for the above switch when it failed or for some other heater fan.
You can still get the Smith's switch thru Nisonger's or any other Brit car supply, but they are all repro now.

[east high]

Smoke screen and oil slick.

[willincalgary]

Smoke screen and oil slick.

I wish. My oil slicks are very unintentional.

[willincalgary]

Actually, the control next to the choke IS original, although optional. It's to turn on and adjust the speed of the Smith's heater.
The other switch is probably an add on for the above switch when it failed or for some other heater fan.
You can still get the Smith's switch thru Nisonger's or any other Brit car supply, but they are all repro now.

The piece in the engine bay looks like it may have been some sort of circular potentiometer for controling the fan motor speed.

I have a Kodiak (?) heater now with an on/off switch. I should be able to hook up some sort of speed control on it. I assume that no damage will occur if I vary the voltage in a similar way on it?

[cedryck]

I think they operated the for and aft machine guns. Oh and let's not forget the tire deflating "tacks" that discourage tailgating.