1 Peso Pattern, Classic Eagle, Copper-Nickel

Pattern coinage from Mexico's late 1970s monetary reform period, when the Banco de México was actively testing alloy and size combinations ahead of the peso's redesign. The Classic Eagle motif had anchored Mexican coinage for decades, but rampant inflation — the peso lost roughly half its value against the dollar between 1976 and 1982 — was forcing reconsideration of the entire circulating series. Copper-nickel trials like this one were evaluated against cost, durability, and vending machine compatibility before final alloy decisions were locked.

PL#146D is one of several documented pattern variants for this denomination from 1979, distinguishable by composition rather than die.