Looks like I was wrong about the ground at the cut-out. There is a chassis ground. Sorry about that folks. The changes in electrical design between 1936 and 1939 is crazy.
To me it looks like the wire coming from the hole inside the generator housing going to the cut-out is a coated wire. The size of the wire coming out of the cut-out is unknown because it runs through a cloth covering but one would think it is a large conductor. The smaller cloth covered wire, coming from the connector on the generator housing, goes to the lighting switch.
1937 generator with a cut-out is model 948-R (truck?). The generator with a regulator is model 960-G (car?).
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
