Watch List notes:

Potosi, Bolivia, cob 8 reales, 1650 O, with crowned-F (Mastalir Fa1) countermark on shield, rare, Mastalir Plate. S-P35; KM-19b; Cal-1488. 20.52 grams. Thin from corrosion but very well detailed and nicely toned, with choice full shield and cross, bold countermark at very edge, bottom of 0 of date visible (one of three known with 1650 reverse muled with 1649 obverse). Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 71 in Part A and page 324 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 certificate. From: Capitana, sunk in 1654 off Chanduy, Ecuador
($350-500)