Here is the completed battery box. I made it out of 16 gauge steel. The interior is insulated with thin EVA craft foam to prevent shorts. The toggle switch is for lights, the ports are the test terminals and the charge port for the ryobi battery that is in the box. The lowest switch is the lighting CDI on/off switch. The box between this battery box and the saddle is one of those blue plastic junction boxes. All the electrical connections are made under this "cap" with wire nuts. This will allow me to remove the battery box easily for servicing.
And here is the horn mounted on the front fender.