Watch List notes:

Potosi, Bolivia, cob 8 reales, (1651) E/O, with uncommon crown-alone (Mastalir K5) countermark on cross, rare, Mastalir Plate. S-P36; KM-19b; Cal-1490. 24.55 grams. Choice full countermark (popular as identical to ones seen on silverware from the Atocha [1622]) in center of full cross, full but partially flat shield with clear P-E/O to left and 8-(E/O) to right, full crown, minimal corrosion, light toning, small edge-crack. Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (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 certificate from the salvors (Maritime Explorations, Inc.). From: Capitana, sunk in 1654 off Chanduy, Ecuador
($300-450)