Cuba, 50 centavos, short key countermark (1872-77) on a San Luis Potosi, Mexico, 50 centavos, 1872O, PCGS VF25. KM-R5.1. Attractively rainbow-toned host (scarce), very bold incuse countermark, popular and important issue from the time of Cuba's "Ten Years War" against Spain (1868-78). PCGS #37523539.
Estimate: $500-1000