Help with Proof

[Whatacoin]

Ok so I did a second search on my copper pennies and found a 1974 (s) penny... I know the mint took ofver proofing after 1968... The penny has some charteristics of a proof but not all... Any ideas And also did the san fransico mint only make proof after 1968?

 

[Generic_Lad]

I believe that 1974 was the last year that the San Fransisco made pennies with "S" mintmarks on them for circulation. Of course, a 1974 proof penny will also bear the "S" mintmark.