I just bought several tubes of pennies from a buddy at work. He had gotten them at an estate sale.
The tubes contained several wheat pennies, including several with the "S" mint mark. Of course, the "S" did not mean that the coins were proofs - that didn't start happening until 1975.
In addition, there was at least one entire tube of 1960 pennies, uncirculated, a couple of tubes of 1961-S pennies uncirculated, and a tube of 1968-S pennies, uncirculated. These pennies are as bright and shiny as if they had just been released from the US Mint!
I have a few of them up for trade, and will be adding more soon! Check 'em out!