1915 Panama Pacific Double S

There are a couple of variations of repunched mintmarks on the 1915 Pan-Pac half-dollars struck at the San Francisco Mint, they are termed "North" and "East" based on the location of the first and more weakly struck mintmark vs. the second and stronger mintmark. For example, if the first/weaker mintmark is to the right (east) of the second/stronger mintmark it is referred to as an "East" repunch.

I'm not aware of a census of how many coins are known with one or the other repunch, but they do appear in auction on a somewhat regular basis. There are a couple of books out there on repunched mintmarks (RPMs), you might want to consult one of them. Based on the auction results I've seen, the Pan-Pac half-dollar RPM does not appear to elicit any real premium over non-RPM coins of similar quality/grade (even in mint state grades).

From the images you posted, it appears your coin might be an "East" RPM coin. It also appears to be a circulated example of the coin. As a comparison, I have an MS-64 example of the coin that shows a similar weak ‘S' to the east of the primary mintmark -- I paid the going rate for a nice PCGS MS-64 example at the time, but no premium for the RPM.

Hope this helps!

Another exceptional reply by our resident expert commems ... of which I can add nothing of substance.

David