1968 United States Mint Proof Set, 5 Coins Inside!!. A very small number of Proof 1968-S Dimes were struck ...

1968 United States Mint Proof Set, 5 Coins Inside!!. A very small number of Proof 1968-S Dimes were struck without a mintmark. Although Proof coins were being struck at the San Francisco Mint at the time, responsibility for making the Proof dies (and adding the mintmark) rested with the Philadelphia Mint. Apparently, at least one die was sent from Philadelphia without the mintmark and a small number of "S"-less Dimes were struck and released before the error was discovered. Less than two dozen of the "S"-less 1968-S Proof Dimes are known to exist. Because the "S"-less Proof sets are valuable, be sure to examine the case for signs of tampering and substitution. Do not purchase an individual "S"-less Dime or complete Proof Set unless it has been authenticated by an expert.A number of different and exciting very rare varieties may be hiding in your 1968-S Proof Set:• Doubled Die Obverse Cent – check "IN GOD WE TRUST" and "LIBERTY"• Doubled Die Obverse Dime – check "IN GOD WE TRUST" and "LIBERTY"• Doubled Die Reverse Dime – check any of the reverse lettering, the torch, and the leaves• Doubled Die Obverse Quarter – check "IN GOD WE TRUST", " LIBERTY", and the date• Doubled Die Reverse Quarter – check any of the reverse lettering• Doubled Die Obverse Half Dollar – check "IN GOD WE TRUST"Original packaging: The individual coins of the 1968-S Proof Set were inserted into holes in a black plastic insert, then sealed in a two-piece, clear plastic case. The case was then inserted into a protective outer cover consisting of blue cardboard imprinted with "United States Proof Set • 1968."