1992年中國古代科技發明發現系列。加厚幣一組五枚。1）10元。航海造船。 NGC PROOF-69 超浮雕。 KM-P21 (cf.KM-404).2) 10 元。指南针。 NGC PROOF-69 超浮雕。 KM-P22 (cf.KM-407).3) 10 元。地震仪。 NGC PROOF-69 超浮雕。 KM-P23 (cf.KM-405)。4) 10 元。蝴蝶风箏。 NGC PROOF-69 超浮雕。 KM-P24 (cf.KM-406).5) 10 元。青铜加工。 NGC PROOF-69 超浮雕。 KM-P25 (cf.KM-408)。预设发行量：2,500。罕见且华美的套币，整体出眾，每枚均银白璀璨，几乎完美无瑕。对於现代币收藏家来说，真正的罕品，连证书。CHINA. Inventions & Discoveries Series Silver Piefort Proof Set (5 Pieces), 1992. All NGC Certified.1) 10 Yuan. Ancient Ship Building. NGC PROOF-69 Ultra Cameo. KM-P21 (cf.KM-404).2) 10 Yuan. First Compass. NGC PROOF-69 Ultra Cameo. KM-P22 (cf.KM-407).3) 10 Yuan. First Seismograph. NGC PROOF-69 Ultra Cameo. KM-P23 (cf.KM-405).4) 10 Yuan. Ancient Kite Flying. NGC PROOF-69 Ultra Cameo. KM-P24 (cf.KM-406).5) 10 Yuan. Bronze Metal Working. NGC PROOF-69 Ultra Cameo. KM-P25 (cf.KM-408).Set Mintage: 2,500. An elusive and desirable set with this one being among the best assembled, with each example being virtually white with surfaces that border on flawless. A real prize for the modern collector, this set is also being sold with the original COAs.
