I would agree that there is next to no chance the treasure hunt is real.  That being said, still interesting.  I'm not sure if I've ever posted this publicly or not.  I guess my best evidence that this could be coin #10 is that this picture (prior to the addition of gold plating) was sent to me on 2/5/15 which seems to line up perfectly with the time frame.  That being said, this one may have a similar back design and the size seems to be about right, but the denomination clearly stands out as being unique.