8 Reales "Birmingham" Forgery by Forum Member Swamperbob
This one is a "Birmingham" forgery - made in England between 1796 and about 1820. It is a Sheffield plate copy of a Mexico City 8R of Charles III with a fake counterstamp of the Bank of England - the portrait is George III. Originals of this coin gave rise to the limerick - "The Bank (of England) in order to make its money pass, stamped the head of a fool on the neck of an ass."
A Sheffield plate is a sandwich of two thin layers of silver over a core of brass or copper. This technique was introduced in Sheffield, England to make inexpensive silver flat ware. It got taken over by counterfeiters shortly thereafter. The silver is usually 0.900 fine so that the surface color was right. The layers were hot or cold welded with high pressure rollers. The material was drawn out to the proper thickness and cut with a cookie cutter. The edge where there was exposed copper needed some cover up work, but they were very good copies.
Die work was decent - some dies were attributed to Matthew Bolton himself but some like this one are not perfect, so that it would be possible to detect them without the test cuts.
The original Birmingham issue (of the two) was done at the outset of the war with Spain (1796). These do not have the counterstamp. The mint facilities in Birmingham produced tens of thousands of these with the indirect support of the English government. They were exported to the orient. It was hoped that the influx of "bad" Bustman dollars would destabilize the Spanish monetary system. The majority of these coins were discovered and destroyed rather quickly and the effort was a failure. Within a very few years, Spain had published a list of 18 dates that it attributed to the Birmingham mints. This list is incorporated in Coronado's book on Spanish counterfeits. They are detectable by their use of incorrect fonts and by the way they are edged. The Birmingham product used a single die edger and applied a strip of silver on the edge to cover the core. The usually have a single overlap of the edge detail and often have rolled edges - not sharp ones like originals.
The second and far more common type of Birmingham is the type you have. These were made in the same mints often with the same dies. Some experts believe many were simple "leftovers" from the earlier effort. These coins are counterstamped with the George III puncheon. These stayed at home in England and were so common that they gave rise to a special act of Parliament. Prior to that it was technically not illegal to copy token coinages.
For those who may not know - the Geo III punch is one of three attempts by the Bank of England to get silver back into circulation during the monetary emergency of the very early 1800s. England was at war and needed money to fight but they also were trying to hold the line on the value of the pound sterling. World silver prices were high so any "full weight" coins issued would immediately be melted for the silver - so NONE were made. Old worn coins (down to 50% or so) remained in circulation. So the Bank took 8R coins and stamped them to raise their face value above the silver content. These would not be melted. This caused the counterfeiters to drag out their presses.
So that is what you have. The 1781 is actually the earliest date attributed to Birmingham. They were made until the late teen's of the 19th century.
Although they are common - they are very popular and bring high prices.
Numerous punches are known. There are some cases where the real punch is used on a counterfeit coin as well.