After building and resolving the problems with the front lights, a shortage of suitable rear lights for Wendy's bicycle started me scouting around for alternatives.
Purchasing another bicycle tail light was out of the question. Either they were cheap junk, weak battery and globe, or part of very expensive sets that didn't suit our bicycle riding style or provide sufficent light.
The obvious solution was to look at vehicle lights, and specifically trailer lights. I was actually looking for a single globe light, but eventually purchased a dual globe light, which I then proceeded to modify.
The various steps are listed in the following pages.