Collection of Commemorative Plates Royal Copenhagen July 4, 1776 plate 7"dia., Commemorative January 1, 1974 milk glass plate 8"dia. 1976 blue glass commemorative plate 8"dia., 8" colonial white milk glass plate, powder blue 8"dia., commemorative plate. Collection of Commemorative Plates Royal Copenhagen July 4, 1776 plate 7"dia., Commemorative January 1, 1974 milk glass plate 8"dia. 1976 blue glass commemorative plate 8"dia., 8" colonial white milk glass plate, powder blue 8"dia., commemorative plate.