Alan, thanks for the picture of the patent plate. A particular curiosity with regard to the Canadian plates is that in 1938 when the Detroit-built products went for 1 year only to a decal for the patent plate, the Windsor plant continued to use a metal tag.
I don't know how familiar you are with the Canadian-built Packard products; you may find this article from the 1937 Canadian Auto Trader interesting as it highlights the sourcing differences between the Detroit and Windsor products.
Also, a photo of the first Canadian-produced Packard, 1931. The Windsor plant closed when England declared war on Germany in 1939.