Korea, Joseon Dynasty. Sang Pyong Tong Bo; 1 Mun. Special Army Unit . 1742 AD. (4.81g; 24.6mm). O./ 常 平 寶 通 [Sang p'yong tong bo; Department of Korean Yi Dynasty, currency unit]. R./ 营 一 ( (Yong): Special Army Unit, (Yi) Series 9, Circle to Left]. Mandel#25.3.1 $16