Qing Dynasty, Emperor Sheng Zu, Engraved Master "Lo-han" Cash 1713 XF Details (Engravers marks, Clay residue), Board of Revenue, design as Hartill-22.91, 25mm, 7.46gm. Obv. Kang Xi Tong Bao. Rev. Boo Chiowan. Extremely rare. From The Valley View Life Collection