Watch List notes:

Potosi, Bolivia, cob 8 reales, 1650 O, with crowned-arms (Mastalir Asa) countermark on cross, rare, Mastalir Plate. S-P35; KM-19b; Cal-1488. 26.58 grams. Broad flan with full crown and most of legends including full 650 of date (Spanish 5), great full shield and cross, bold full P-O and 8-O with dots only below the O's (a unique subtype), the countermark typically partial and at the very edge on the cross side (8 to 9 o'clock). Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 87 in Part A) 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
($400-600)