Watch List notes:

Potosi, Bolivia, cob 8 reales, (1650) O, with uncommon crown-alone (Mastalir K5) countermark on cross, rare, Mastalir Plate. S-P35; KM-19b; Cal-1488. 19.35 grams. Broad flan, thin from corrosion, nicely toned, with full but somewhat weak shield and cross, clear P-O and 8-O, bold king's name and ordinal, date not visible but attributable to 1650 by style, very weak but apparently attributable countermark in center of cross. Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 85 in Part A and page 291 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 original Herman Moro photo-certificate. From: Capitana, sunk in 1654 off Chanduy, Ecuador
($250-375)