Hello. I have an 1803 Eight Reales with the Mexico City mintmark. It is non-magnetic, and its weight is 27 gr. The thing that stumps me is the assayer's initials. The references I have seen indicate that there was a FM and a TH in 1803, but not a HI as this one is stamped. What are your thoughts? Is this a fake?
Yes, it is a fake. Clearly it was made from an incorrect pairing of forged dies. Most of the coins packaged in that way are garbage. How do you know it weighs 27g? Did you remove it from the packaging? An accurate weight to two decimal places will probably show that it is actually underweight.