I state that this bike is not mine, is a photo taken from the web to indicate the object of my question.
You can see to the left of the side cover a circular plaque aluminium grey fastened just below the ignition key.
I would like to know if it is the first model of the diode and if was however coupled with the zener diode.
By 1969 wiring diagram I can't find it, probably because it was installed only in 1968.
Some pictures (even as it was attached to the battery tray or side cover) and the number of subject would be appreciated.