Ah! The CB750! I used to have one. I went from that to a 1979 Sportster, and from the Sportster to a 1993 FXR. And I still ride it 25 years later. :-)
It’s sitting in storage until I can get around to it.
A big part of the delay of doing anything has been the “big move” to the new pad.
I wished I knew more about the electrical system. Not long after it was bought, I got a pdf of the factory service manual.