Watch List notes:

Potosi, Bolivia, cob 1 real, 1650 O, rare, ex-Mastalir (Plate Coin). S-P35; KM-12b; Cal-744. 4.34 grams. Holed F/VF with bold assayer initial, somewhat weak yet full shield and cross, slightly overweight. Pedigreed to the Robert Mastalir collection, plated on page 247 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.
($80-120)