Watch List notes:

Potosi, Bolivia, cob 8 reales, 1651 O, with crowned-arms (Mastalir Asb) countermark on cross, very rare, Mastalir Plate. S-P35; KM-19b; Cal-1489. 20.45 grams. Choice full shield and cross on a broad flan (thin from corrosion), with full and clear date (the 16 appearing twice due to doubling) and equally full and clear P-O and 8-O with dots only above and below and between the 8 and O (this being the only example known of this asymmetrical arrangement with clear date 1651), the typically partial countermark at very edge on cross side rather bold and well detailed, brownish toning in crevices all over. Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 124 in Part A and page 63 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 tag and certificate. From: Capitana, sunk in 1654 off Chanduy, Ecuador
($350-500)