MEXICO. Charles IV & Maria Luisa Silver Archbishopric Proclamation Silver Medal, 1789. NGC MS-61. Grove-C-21A; Fonrobert-6405. By G.A. Gil. Obverse: Laureate and draped bust of Charles IV facing right; Reverse: Laureate and draped bust of Queen Maria Luisa facing left. Attractive and flashy, this Mint State medal is rather stunning. With a double headed design, this piece is sure to see spirted bidding.