I finally got around to actually looking at my bikes ignition switch and rectifier. There is a small tab that comes off the frame, inside the battery cover, at the top, in the front, with a 1/4 inch mounting hole. The rectifier mounting stud enters the hole from behind, and captures the ignition switch mounting bracket at the same time. I don't know when the ignition switch was moved from between the coils to this position, but it is an improvement, as far as convenience is concerned.
Mike B.