Actually, they were quite common to find here in Newfoundland after the war; and mandatory equipment on vehicles here during the war. My uncle had a set that he used on his car back then.
I don't believe that there was a set pattern to these shades; provided they met the requirements, most tinsmiths, garages, and even individuals made their own.
Would be hard to determine where exactly they came from without any maker's markings.
Neat find.