[blucar]

looking at the pix you attached, I note that the generator/fan appears to be typical of a gen/fan combo that was used trough '39. If the generator is a two brush unit with a regulator, then it is a '39. Generators prior to '39 are three brush with a "shunt/cut-out", generally sitting on top of the generator.
I also noted that the exhaust manifold is not the '35-36 "log" type.
In time you are probably going to find the the engine originally was either a commercial engine, i.e. truck or a stationary unit of some kind.
The loss of coolant is very common in the pre-pressurized systems. One way to stop the loss of coolant is to leave the coolant level down about 1" below the filler neck. If you can find a pressure cap of about 4lb's that will fit the radiator neck, then you can add an overflow tank "coolant recovery", attached to the overflow tube, which will capture the expanded coolant and return same to the radiator when the system cools down. The coolant recovery tank will also eliminate air entrainment in the cooling system and thereby make the system more efficient.
Neat looking truck.. The application of car front ends on '36 Ford pickups has become quite common here in the states with the Street Rod types. The cab on your truck is very unusual..
Does the truck have hydraulic brakes?