40 Centésimos de Real

The Casa de Moneda de Montevideo opened in 1840 under extraordinary circumstances — Uruguay had only declared independence from Brazil in 1828, and the new republic was already mired in the Guerra Grande, the brutal civil conflict that would drag on until 1851 and pull in Argentine and Brazilian forces alike. This coin was struck in the thick of that war, with Montevideo itself under siege from 1843 onward.

The 40-centésimo denomination was effectively orphaned by the monetary chaos of the period and saw limited subsequent issues, making survivors in any grade genuinely scarce.