The gold bodywork was only available after 19, xxx serial number.
So....
Z sandcast wearing gold tins has been switched.. but jt could have happened in spring of 70..
So ...
If it wore those tins since 70, and is documented.. I think that would be best case scenario..
I think at least one prototype was done in gold, i think the Brighton bike..
Long before it was z production choice.,
Now sometimes bikes get tins swapped at dealership at time if sale.
So it is posdible a dealer still had a sandcast on the floor in spring of 70 and a K0 in gold , and customer requested a swap. THIS with Documentation of the sale occuring after gold was introduced, or a receipt mentioning the swap... could be very important..