This is the illustration I was thinking of. And when I look at my early literature, admittedly all the photos show the simple silver stick-on Norton Villiers badge (part number 06-0499), rather than the N15 style. So perhaps mine is not correct after all. The tank has a large recess under the tank badges, and the round N15 badge cover the recess quite nicely. How does the thinner stick-on Norton Villiers badge work here. Does it fit in the recess, span it, conform to it, or what?
And no possum, I doubt my bike was mentioned in Old Bike Australasia. It is located in Victoria, British Columbia.
Stephen Hill