Tiny,
Full disclosure, what I know about the three brush Delco Remy generators and cutouts comes from personal experience with old John Deere tractors and reading old motors manuals.
I assume the old Chevy systems worked the same way, but I have never owned one, so I may be talking out of my hat. But if it were me, I would try the 3 pole regulator with the existing generator before replacing everything. Actually, if it was me I would regard it as a proper challenge to get the existing system works as per factory. LOL.
Here is a link that may be of interest. I think the truck generator was the 943-J.
1935 Chevy Generator system. Kurt
