Watch List notes:

Potosi, Bolivia, cob 8 reales, 1651 O, with crowned-T (Mastalir Ta) countermark on shield, rare, Mastalir Plate. S-P35; KM-19b; Cal-1489. 24.78 grams. Choice full countermark near center of shield with faint but certain P-O to left and 8-O to right, full king's ordinal IIII, the cross side weak and corroded but with most of 5 of date visible, crack in edge and a few small dark spots. Pedigreed to the Roberto Mastalir Collection of Countermarked Potosi Cobs, Plate Coin (page 314 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 copy of Herman Moro certificate. From: Capitana, sunk in 1654 off Chanduy, Ecuador
($300-450)