40 Réis - Pedro V Countermarked over Pataco - João VI, Portugal

The pataco — the colloquial name for João VI's 40 réis coppers struck from around 1812 onward — circulated widely across Portuguese colonial territories long after their metropolitan usefulness had expired. São Tomé and Príncipe, chronically short of small change, solved its currency problem in 1854 not by requesting a new issue from Lisbon but by simply countermarking existing patacões already in local circulation, officially revalidating them under Pedro V. The KM reference remains unresolved, reflecting how inconsistently these colonial countermark operations were documented by the Casa da Moeda.