Watch List notes:

Potosi, Bolivia, cob 8 reales, 1650 O, with crowned-PH (Mastalir PHca-ao) countermark on shield, rare, Mastalir Plate. S-P35; KM-19b; Cal-1488. 24.24 grams. Solid and round flan (light surface corrosion only) with edge-crack, no toning, with full shield and cross, clear P-O and 8-O, bold 50 of date, and most of countermark on shield, the peripheries flat. Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 367 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 photo-certificate. From: Capitana, sunk in 1654 off Chanduy, Ecuador
($300-450)