MEXICO. Banco Mercantil de Monterrey. 50 Pesos, ND (ca.1906). P-S355As. Specimen. PMG Superb Gem Uncirculated 67 EPQ.(M427s2). A scarce Mercantil de Monterrey banknote printed by the American Bank Note Company. Orange underprint with a vivid portrait at left, and vignette at right. Punch cancelled at the signature panel.