Since at least July 2017 Ebay seller crazycardinal24 from Saint Louis in Missouri has been selling these replica US plates.
He or she is selling Indiana and Missouri replicas. I am sure there are other ones also that I have not found.
I am told many of these are very close to the genuine plates although the separator on the 1942 Missouri plate (that is not close to the original at all) is wrong and the other Missouri ones that should be enamelled (porcelain) are only painted.
For photos of genuine early US plates please see Eric Taylor’s excellent site http://porcelainplates.net/
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.