When Radio Shack had electronic parts and not just cell phones and imported toys, they had a little SPST push button switch that fit the hole and the space inside, and works great. You bypass the headlight cutout - that has never caused a starting problem for me. The Honda switch melts from having the headlight power through it all the time; once the switch contact gets a bit corroded it runs very hot and soon fails. Adding a headlight power relay solves that problem if you have (or get) a stock switch, and your headlight will be considerably brighter if you run a power wire for the lighting circuit to the relay straight from the main fuse. All the wiring - the headlight power goes through the ignition switch, many bullet connections, and the starter switch - means it ends up getting a few volts less than battery voltage.
