Watch List notes:

Lot of four Potosi, Bolivia, cob 1R, (1650-2), assayers O and E, ex-Mastalir (Plate Coins). KM-12b. 12.01 grams total. All more or less rare, one with partial 1651 date visible, grades around VF to XF (one with some porosity). Pedigreed to the Robert Mastalir collection, plated on pages 253, 254 and 258 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.
($200-300)