American Ebayer 14recycling was selling these two plates in March 2013, says that he got them in Laos and he was told that they were old car plates. 14recycling of Chesterfield, IL and spfroc of Pioneer, CA appear to be the same seller.
Old they may be but they are not Laos vehicle plates at all. Plates from Laos have always had letters on them as well as numerals.
Just because a plate is old, it doesn’t mean it is genuine. Check with the photo archives.