Ignition Coil mount is a simple 1/8" thick tab welded to frame with 1/4" holes drilled for mounting bolts. The coil is a simple 12v automotive ignition coil, nothing special, available at any discount auto parts store. Photo makes it appear larger than it really is. Position of the coil is a compromise between keeping the mass of the bike centered and low and trying to keep the spark plug lead as short as possible. I made a the cinch strap that goes around the coil by wrapping some 24 gauge steel around the coil and bending a couple of right angle tabs. I drilled the tabs to find the mount, slipped the bolts through and as you tighten up the bolts it cinches down on the coil for a nice tight fit. Paint it satin black and mount it with 1/4 - 20 socket bolts and Nyloc nuts. Note in this photo the green spring added to clutch arm at the base of the cylinder, this was added to give the clutch lever more feel, the jockey was complaining you see.

A poor quality photo showing the coil with ballast resistor installed (white thing above coil with two wires connected to it) This is a 1.2 ohm resistor, I found that the coil was getting too hot when I did not use it. Since the coil is an automotive type it is designed to fire up to 4 times per revolution of the crankshaft (V8), in this application it will be firing only once for every rotation so it will have plenty of time between firings to charge the windings.