I put the horn in the front under the steering head. The coil bracket is a piece of 1/4 inch steel cut in the shape of a "T" turned upside down with a 1 inch dia. by 3/4 inch aluminum spacer bolted to the old horn bracket. I removed the seat post and cut the coil cover bracket off to mount the cover on the new one.
Looks good. Considering this mod myself. I want to run the coil out of my horn cover shown below. Thinking stainless steel braided spark plug wires and running the horn in front of the mudguard.