Jim,
The CR750s didn't have much electrics to speak of. No lights, blikers, horn, or starter. Some of them used a magneto that was added-on so they didn't even need a battery. What little electrics there were, were under the tank.
Got a pic of your tank? I'd love to see it, as you know, I'm planning a CR750 replica of sorts, too!
Sherm
Here's a pic of Mitch Boehm's vintage CB750 racer built by Patrick Bodden, featured in Motorcyclist/Sportrider magazine.