In the proof set pictured below, on the obverse of the Kennedy half, it appears that the S mintmark is stamped above something else. What it is i can't make out but perhaps one of you have come across it before.
It is peculiar I blew up 8x all I have handy. My guess would be perhaps a cud or chip then stamped to make a weird mintmark. But no means in my wheel house! I'm sure Paddyman and/or others will nail this down and quick! Good luck and thanks for sharing
@expat @David Betts I'm inclined to agree with John. I just looked at the two sets I have, and the mintmark on both Kennedys are perfectly struck into the die by hand, of course! ~ Chris
I agree there is a spot near the mintmark, but it is the large, indented shape under the S that i am enquiring about. I have another set as well and there is no indented shape under the S on the other one.
The image is far too small for me to see it well. Keep in mind that the mintmark was hand-punched into the die, and if it was initially placed incorrectly, there would be a slight depression on the die. This would create a raised mark on the coin. But, this is not the case on your coin. I can't think of anything that would cause this sort of depression on a proof coin. ~ Chris
It's interesting, I would like to see a photo from directly above, kind of a pain with out a stable camera. The top of the S is weak in the photos. Maybe a slightly filled die?
I have tried different lighting and camera angles and it still looks like either a poor die or doubled die. What i don't get, it's a proof, don't they normally try to achieve almost perfection
I think it is a normal MMS for the coin. Your photos aren't clear enough to confirm anything other than that. It is a MMS-2 this MM style shows doubling. It also has some evident die chips http://varietyvista.com/12 Kennedy Halves/San Francisco Mintmark Styles.htm