Heat sink zener diode

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.
Thanks.
Piero

Re: 1968 circular diode?

good to see your constantly on the job Piero.
The aluminium discs are only the heat sink not the actual diode,
I recall duplicating this for my 63 650SS " I think it was" for some "authenticity" I just sandwiched some aluminum discs
with washers all held together by the normal Zenor diode, on that bike it was mounted about where the left front tank mount is, not really answering your question but I'm sure your answer will be forthcoming,... Lab???????

Re: 1968 circular diode?

Hi and thank you.
I hope things are going well in your country.
Ciao.
Piero