It is somewhat sterotypical to suggest that electrons have a unique tendency to escape from British bikes, and that Lucas is in fact the lord of darkness. However, my experience with multiple pieces of British iron is that there is some apparent truth to the matter. The bike ran and started fine last year. It has been lovingly stored in a dry and relatively warm garage. It has a new battery. It has beautiful paint. And turning the key does nothing. No lights, no neutral indicator. Nothing.
Hours of searching leads me to a horn wire that was grounding out, but removing that changes nothing. It is a mystery of how it would ever had run if that horn wire was the issue. Typical mystery not confined to Brit iron (To Spark or not to spark and On getting Grounded). Hours more and it was obvious that for no apparent reason, there was no juice at the ignition switch. I changed the horn from the Stebel to a common aftermarket one, provided a path to the key switch, and voila we have ignition. Armed with air, fuel, and fire, the machine show signs of firing after just three kicks, but finally fired after about twenty.
Something happened within the harness over a four month period that shall remain a mystery. It is a 40 year old machine, and I'm glad it is running, but it does add to the stories floating around about sudden mysterious electrical challenges and British bikes.