Demon Electric choke

Inside that choke controller are 2 of what is inside the mechanical gauge voltage limiters, resistor wire wrapped on bimetal beams. It controlled the voltage to a heating element like what is on a range. The thing wasn't weather tight so it could very well be rotten inside. FSM should say how to test it but I doubt it will operate a choke that is supposed to get 12 volts.
If I was going to add anything to a aftermarket choke it would be a timer like a rear defrost timer.