1980年30元加厚精制套币。冬奥会。四枚一组。1) 30元,速滑。获评NGC PROOF-69 Ultra Cameo,2) 30元。高山滑雪 。获评NGC PROOF-69 Cameo。3) 30元。冬季两项。获评NGC PROOF-69 Ultra Cameo。4) 30元。花式溜冰 。获评NGC PROOF-69 Cameo。CHINA. 30 Yuan Piefort Proof Set (4 Pieces), 1980. Winter Olympics. All NGC Certified.1) 30 Yuan. Speed Skating. NGC PROOF-69 Ultra Cameo. KM-P15.2) 30 Yuan. Downhill/Alpine Skiing. NGC PROOF-69 Cameo. KM-P16.3) 30 Yuan. Biathlon Skiing. NGC PROOF-69 Ultra Cameo. KM-P17.4) 30 Yuan. Figure Skating. NGC PROOF-69 Cameo. KM-P18.