I had a parallel experience of deteriorated wiring on a 1978 CT90, which resulted in strange voltage readings that could not be explained until I started testing for resistance and ran some supplementary wiring to get more volts to where they were needed. I am sure it is not as common as selenium rectifiers and old flooded lead acid batteries needing to be replaced, but it seems to be another problem to be considered.
I remember owning a mid 1970s C70 in the mid 1980s and the challenge of dealing with the sub-optimal 6V battery and its "load balancing" design. To me it seems a much more fundamental challenge for these little old motorcycles than having to learn how to fettle with rusty tanks, carburettors and breaker points. Getting spark is of course what everyone thinks about in dealing with a newly obtained old Honda, but getting it to run so that it does not run the battery dry (or in my nightmares turn a sealed battery into an IED) or have lighting that is too weak to get home in the dark. These seem to be the real challenges of these old bikes staying useful for transportation.