Watch List notes:

Potosi, Bolivia, cob 8 reales, 1649 O, with crown-alone countermark on shield, ex-Mastalir (Plate). S-P35; KM-19b; Cal-1487. 17.96 grams. Very bold full countermark in center of shield, with some concavity and an edge-split as a result, full P-O and bold 9 of date, full shield and cross, thin from corrosion but nicely toned. Pedigreed to the Robert Mastalir Collection and plated on page 176 of Part A and page 275 of Part B of his books The Great Transition at the Potosi Mint, 1649-1652: The 1649-1652 Crowned Shield Coinage and the Countermarks of 1652 (2021), with certificate.Recovered from: Capitana, sunk in 1654 off Chanduy, Ecuador.

Estimate: $350 - $500