This is the Superflex Engine Heater, a part of the Cold Starting Stove Kit Part No. A-7156.
The fuel tank mounts on the outside of the engine bay on the fender and cowl step.
The Superflex heater was made by the Perfection Stove Company of Cleveland, Ohio.
The Cold Starting Stove kit is just one of several sub-kits in the overall Winterization Kit for the World War Two Willys MB or Ford GPW. Unfortunately, I do not remember who to credit with these pictures. If these are yours please drop me a line so that I might credit you.