Brazil
João VI 960 Reis 1817-R AU Details (Plugged) NGC, Rio de Janeiro mint, KM307.3, Russo-P427. Struck over a previously plugged Charles III pillar 8 Reales with undercoin details faint but discernible, including the king's name under "NATA" and shield on the reverse. A very rare combination with the previously plugged base coin a rare ocurrence in the series since defective coin were unlikely to be overstruck.
Estimate: 3000-4000 USD