I have to agree with Greg. A store I worked at in the '70's carried Triumph and Norton. 99% of the electrical problems. were customer induced. Everyone "knew" that Lucas wiring was trash, so everyone and their buddy "fixed" it. No one could understand the concept of positive ground. "Those Limeys are DUMB, man." The finned Zener Diode in the breeze under the head light was "ugly", so it was often removed or put under a side cover. It regulated voltage by dissipating excess voltage as heat. The wiring was fixed with house and/or speaker wire. Connections were twisted together with house wire nuts, or taped. Left stock, with clean tight connections, the Lucas system was pretty good. Not as good as modern Japanese stuff, but good enough.
Even on modern Enfields, most of the electrical issues I get are a maintenance issue. As part of my PDI I tighten and clean connections. When I modify something I use proper gauge and type wiring with quality connectors or solder.
Taken a step farther, most of the electrical issues on the Japanese bikes I get through here suffer from the same customer induced "fixes". I don't know how some of these bikes avoid lighting on fire.