GREAT Lot of (1) 1956 US Mint Silver PROOF Set, w/ 90% SILVER COINS, in OGP, in UNOPENED ENVELOPE. Pics are part of description. Years ago, sealed by the Mint, and getting harder to find in UNOPENED state. See my other coin listings and thanks for looking. See below for list of coins. 1 – 1956 US Mint SILVER PROOF Set, w/ 90% SILVER COINS, in OGP, in UNOPENED ENVELOPE. Perfect for competing a Silver Proof Set run, or looking for CAMEO coins!!