Pattern Halfcrown, 1817, by Thomas Wyon after Pistrucci's model, smaller laureate bust right, date below, GEORGIUS III DEI GRATIA, rev. by Benedetto Pistrucci, crowned shield of arms within garter, with extra garnishing overlapping, toothed border both sides, BRITANNIARUM REX FID: DEF:, edge milled (ESC 627 R4), as struck, deep purple tone, extremely rare