Potosi, Bolivia, cob 8 reales, 1651O, Latin 5, with crowned-•F• (two dots) countermark on shield. S-P35; KM-19b; CT-510. 23.51 grams. Choice full countermark, full but doubled shield, full but weaker cross, full date, corroded near edge and with two large edge-splits, lightly toned all over. From the Maravillas Research Collection of Countermarked Potosi Cobs, with Marex certificate and tag #0058. Recovered from: Maravillas, sunk in 1656 off Grand Bahama Island ($300-450)