The New York Bank Hoard. 2016 china proof gold & silver dazu rock carvings set-2 ngc pf70 uc er sku42687 perfect grades with great wall labels. Why choose this Proof 70 Ultra Cameo 2016 China Dazu Rock Carvings Gold and Silver set with exclusive Great Wall labels? Both coins in this set received the grade of Proof 70 from the Numismatic Guaranty Corporation (NGC).