Looks like an excellent job of troubleshooting, diagnosis, and repair! I'd love to get some test equipment onto one of these old rigs and document just how much charging current they can produce under different ciccumstances such as lights on or off, medium engine speed, highway speed, etc.
The most recent use of 3-brush generators and cutout relays was on farm tractors, stationary engines such as irrigation pumps, etc. where the engine was started once and ran for hours without being shut down. Bacically a trickle charge system.
Jerry
