Watch List notes:

Potosi, Bolivia, cob 1 real, 1650 O, assayer as dotted C to left, rare, ex-Mastalir (Plate Coin). S-P35; KM-12b; Cal-744. 2.19 grams. VF with some surface corrosion yet clear and rare assayer as dotted C, off-center but nearly full shield and cross. Pedigreed to the Robert Mastalir collection, plated on page 248 of his 2021 book The Great Transition at the Potosi Mint 1649-1652 / The 1649-1652 Crowned Shield Coinage and the Countermarks of 1652 / Part A: The 1649-1652 Crowned Shield Coinage.
($70-100)