Watch List notes:

Potosi, Bolivia, cob 8 reales, (1651-2) O or E, with crowned-O (Mastalir O4) countermark on cross, unique, Mastalir plate. KM-19b. 10.16 grams. Very thin from corrosion but with one bold castle and one bold lion above a partial countermark that Mastalir has identified as a crowned O of a unique style, the shield side almost totally blank, darkly toned all over. Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 200 in Part B) in his book The Great Transition at the Potosi Mint, 1649-1653, The 1649-1652 Crowned Shield Coinage and the Countermarks of 1652 (2021), with copy of Herman Moro certificate. From: Capitana, sunk in 1654 off Chanduy, Ecuador
($150-225)