Watch List notes:

Potosi, Bolivia, cob 4 reales, 1649 O, with crown-alone countermark on shield, ex-Mastalir (Plate). S-P35; KM-17b; Cal-1105. 8.52 grams. Thin from corrosion but with about half of shield showing bold full countermark, bold P-O to left, good full cross displaying an interesting brockage of the countermark from the other side, bold full 49 of date, nicely toned, minor edge-split. Pedigreed to the Robert Mastalir Collection and plated on page 68 of Part A and page 283 of Part B of his books The Great Transition at the Potosi Mint, 1649-1652: The 1649-1652 Crowned Shield Coinage and the Countermarks of 1652 (2021), also pedigreed to the Ponterio auction of October 7, 2000, with original lot-tag 1303 and original (generic) Herman Moro certificate.Recovered from: Capitana, sunk in 1654 off Chanduy, Ecuador.

Estimate: $400 - $600