More regarding Spanish Colonial coins with piercings:

The circa 1680 Isla Santa Clara shipwreck site off of Ecuador, which carried
pre-screwpress era Spanish Colonial cob coins ranging from the reigns of
Philip II to Carlos II, produced a number of pierced coins, as did the 1622
Fleet, Nuestra Senora de Atocha shipwreck in the Florida Straits, which
carried pre-screwpress coins ranging in date from the reigns of Carlos and
Johana to Philip IV. If memory serves me right, the earliest pierced coin
that has come to my attention was produced during the reign of Philip II.

Carol Tedesco
Historic Underwater Discoveries, Inc.
PO Box 1179
Key West, Florida 33041