Since probably late 2015 Ebay seller tigerpl8s from Pakred, Nontaburi in Thailand has been selling these reproduction early American and Canadian plates from the 1900s, 1910s and 1930s. These are more of the ones I have been able to track down but I am sure there are even more I have not seen.
See also 532-Ebay-tigerpl8s-early-USA-Canada-fake-replica-number-license-plates on page 61 here and 587-Ebay-tigerpl8s-early-USA-Canada-fake-replica-number-license-plates on page 67
He has several copies of each plate and he is correctly selling them as reproductions. He has had them made in Thailand from steel sheet and then painted and lacquered to look very realistic. A few, I believe, may be printed stickers on the sheet. The genuine plates are enamelled (or porcelain as Americans call it).
For the 1930s plates, the Arizona ones are correctly made of copper and have REPLICA stamped on the bottom at the rear. The Newfoundland plate is pretty accurate but the word and date are ever so slightly in the wrong place.
For his newer made steel plates, he has started to write replica on the back or put a sticker. These are not guaranteed to still be there if someone wants to pass them on as genuine.
The genuine plates are very, very rare and most are very expensive. Some people want a reproduction in their collection because there is no chance they will be able to find or afford a genuine one.
The problem is going to come later when some of these plates get into the market or crooks try to distress them and claim they are genuine. From a photo during a sale or trade it will be very difficult to tell if the plate or plates are genuine or not.
This just makes everything difficult for everyone. Reproductions are very bad for the hobby and if you care about the future of the hobby, it is better you do not buy reproductions..