Ok I found a 1971 S penny but cherry pickers list this as a mint set. Was this one removed from one or something else?
Since you have CPG. notice how the separation line such as on the "9" and the *7" that it shows almost equal levels on both, This is expect on DD, as each hubbing should push in fairly deep. On machine doubling, the cause produces a layer that is quite flattened in comparison with the other. One strong image and then the machine allowed movement of the die to create the weaker image. There are several ways such an appearance can occur. Here is a page of good explanations. http://koinpro.tripod.com/Articles/OtherFormsOfDoubling.htm jim
No. It wasn't removed from a mint set as cent production out of San Francisco stopped in 1955 and was resumed from 1968 thru 1974. 1975 did not have an S cent in either circulation or in a US Mint Set.