My small ones range from around '46 to '64. I have not seen a Canadian Sky-Chief Supreme so that particular brand may be U.S. only. All my Canadian signs are made by P. & M. (Porcelain and Metal Signs) and are date stamped in black into the porcelain in the bottom right corner. The 8 x 12" Sky Chief however is in black at the bottom and I haven't seen a Canadian date stamp in white like the U.S. one in the posting above, so no date. There are a number of signs with minor variations such the way the registered trademark is shown just under the green T. Cheers, Don.