1788 Spain Charles III Seville mint silver 2 reales (coins minted for both Charles III and Charles IIII).
Mint director initial apparently re-engraved with C over CF.
CF was used on coinage from 1773 to 1782. A break occurred in Seville mint production until 1788.
Apparently some reverse dies were still available from 1782 with CF for Charles III and at least one of these dies was reworked with a C. Remnants of the F can be seen.
Certified by NGC to F 12.