I'd agree with the fact that the S mints from the 60's and 70's are about as rare as some wheaties. I hardly ever see any S mints when I'm roll hunting pennies. Also, look at the mintage figures the S mints have quite a bit lower numbers, some even 10 fold lower than the other mints. I still haven't been able to find '73 and '74 S at all! They're the only two missing above 1960 in my collection.























