PrinceHarbinger 
Based on what I see in the pictures the coin is not a Class 1 Contemporary Circulating Counterfeit.
It is also not a Class 3 Numismatic Forgery.
In my opinion I would guess that it is a Class 2 Circulating Silver Counterfeit made for the Chinese merchant trade.
The clue is visible on the edge - the overlap is too long and does not align well. This in not typical of Mexico City edges made on a Castang machine using a pair of grooved edge dies. I may be incorrect which leaves the alternative as genuine. However, the market value of the coin would be identical.