I just got an email from www.vintagecb750.com that they are stocking handlebar switches for a pretty wide variety if cb750s. Anyone know if these are OEM or repro, and if repro, are they any good? I gotta say, despite repainting and rebuilding my own switches, I'm pretty tempted by this...
http://www.vintagecb750.com/products/86/new-items
The first 2 switches on the site will drop right in to the K3/4/5/6 bikes. The third switch will fit the F0-F3 and K7/8 bikes.
The only wires that, if undersized, would be of issue would be in the right-hand switch, the START button might need a Relay Kit to prevent switch heating if halogen headlight is used. If stock headlight (Stanley or sealed-beam type) is used, no problems should crop up.
The K0-K2 bikes (like those built for AUS and UK until 1976, US until 1973 early) have an OFF/LO/HI on the right side, and no HI/LO on the left side. This early wiring is different from the switches on this site, but they can be adapted if required. PM me for details if you need them.