Qing Dynasty brass Board of Revenue "Engraved Master" 1000 Cash ND (1854) Choice XF, Emperor Wen Zong, type of Hartill-22.714 & FD-2435, 72mm, 203g. Obv. Xian Feng yuan bao. Rev. Boo chiowan, left and right; Dang qian, above and below. Superb details. Close examination reveals this is a "master" coin, engraved from quality metal after a new design is drawn up. This "master" is presented to the Emperor for approval. The center aperture is unfinished and a small hole, referred to as "Golden Mouth", is bored through the center. When approved by the Emperor, the small central hole is enlarged into the normal square hole. The "master" coin is then used to produce molds for casting "mother" coins. A "master" coin of this large denomination is exceedingly rare,
