It looks like the generator, the water pump, and possibly the distributor share a common drive- - - -most likely off the timing gear for the camshaft.
Jerry
So weird, and cool.
If you look at the ad Dan posted, it speaks of a “ventilated crankcase.” Looks to me like the rear end of that same drive is operating some sort of air pump or such that is pulling vapors from crankcase. Pulling it straight out to atmosphere.
