George III (1760-1820), Emergency issue, a Spain, Charles IV, 4-Reales, 1792mf, Madrid, obv. countermarked with head of George III in octagon (Manville, BNJ 2000, pp.111-12; ESC –; S –). Coin better than fine but with obverse edge knock at 7 o’clock, countermark about fine (£100-200)

The countermark is not from one of the forged punches illustrated by Manville