MOst of the problems with Lucas stuff was that it was slightly different than what we made and guys didn't take the time to learn it. Positive ground being one. I've had a few old trumpets, and any one that I rebuilt with stock electrics never had any problem. I have to confess that my eyes glaze over when the young guys talk about the new electronic stuff, I just haven't kept up.
Another potential problem with the wiring was that the bikes and cars were shipped over in regular crates and plats. (the japs started plastic wrapping their stuff) The salt air on the trip over could wreck havoc on the connections it they sat for a long time, which they often did before sale. Just one theory I heard. I'm with Ian, though. Give me a set of points and a kickstarter anyday.