4 Escudos - Carlos III

Carlos III assumed the Spanish throne in 1759 after ruling Naples for over two decades, arriving to find the colonial minting apparatus already well-established but operating under the older macuquina (cob) tradition. The Mexico City Mint was in the middle of transitioning toward milled coinage — the so-called "columnario" milled series had been running since 1732 — but the 4 escudos denomination in cob form persisted alongside it, creating a parallel circulation of sharply different manufacturing standards from the same mint.

The 1760–1761 dating places this coin at the very opening of Carlos III's reign, before the Bourbon administrative reforms that would later tighten colonial mint oversight considerably. KM#140 cob gold of this period is notably irregular in flan preparation, and assayer attribution can be difficult on weakly struck specimens.