In April 2015 Ebay seller busi_edu_toys from NSW in Australia was selling this supposedly Mongolian plate. The problem is that the design is completely wrong. The font is completely wrong and the layout is wrong.
This is probably a complete fake rather than a rejected test design and the plates that were actually used are very, very different from this.
Why buy such mint looking plates when you really don’t know what a genuine plate should look like. There are hundreds of photos of genuine plates on the www and it is so easy to check if something looks right or not.