Thanks for the replies.
Greg... always good to point out the obvious when I ask a question. The six pages that list the different fasteners get referred to on a relatively constant basis, but never thought to look for information on finish.
Interestingly it states that all series D engines had black covers, but cases, barrels, and heads were unpainted. First bike I think of is the Len Hardy Lightning with the black cases.
I was surprised to see the inner rear spring boxes listed as dull chromium except for the early black ones. Two sets that I have and believe to be original (one appears NOS) are cad plated. They look nothing like dull chrome. If the honourable member from the Saltspring Island section had cad plated front lowers, why would they have done the front in cad and rear in dull chrome. Probably more likely that both methods were used In both locations?
Cad plating is still available here, but the fear of them loosing stuff is a little overwhelming.
Also interesting that the book says spokes were zinc and nipples were cad. At least I can do spokes now.