Looks like Reverse E on Variety #105, but a different obverse die. I don’t see any other ones listed with reverse E. Maybe a new variety? http://www.seateddimevarieties.com/date_mintmark/1887svarpage.htm http://www.seateddimevarieties.com/date_mintmark/1887s_105page.htm
I was thinking along those lines a new discovery but if you compare the other mm same date youll notice filled mm, and repunched some as many as 4.
I was thinking this one .. 1887 S/S VP-001 10C MS NGC Attribution: VP-001 Cross Reference Fortin: F-105 Greer: G-101 Diagnostics The mintmark was repunched west of the first impression.
I thought not, because of the missing curve to the right of the MM, but maybe it's there faintly? Hmm.
This one was an Horzonal strike if you look at it. As well a vertical one that is of a different type S size and shape. The op's coin has 5 serifs you can count .
Send it to Mr. Wiles . Coneca has 2 of them in their listings . http://varietyvista.com/19th Century & Misc Varieties.htm
Wiles has a note that states he is looking for other specimens to compare. After looking at all images my money is on a new RPM. Nice find.
One really ask themselves what the heck was going on at the mint. Perfect example the 1847 /7 lg.cent The underlying 7 is no where anything being used on a US minted coin as such time. The same for this S the font is totally different than the primary mm . And think about it where else have you seen this script or font? We're these errors or done as a test, or a joke? Who controled the punches? And dies?? Maybe a test die....repurposed to retire a broken die? As I have learned to attribute by die marriages it has made me appreciate more any data kept on record for the nu her of dies used. Some years there are no records kept...thus leading you guessing at times of marriages and remarriages.
Check out this punch ( san francisco ) . Here's a punch that was used between 1941-1952 . MMS-004 (Trumpet Tail) Years of Service 1941 1942 1945 1946 1947 1948 1949 1950 1951 1952 It was also used between 1974-1979 and nothing in between MMS-009 = MMS-004 (New research shows these are the same punch) Years of Service 1974 (ODV-031) 1975 1976 1977 1978 1979 Here's the link to that info . http://varietyvista.com/01b LC Doubled Dies Vol 2/San Francisco Mintmark Styles.htm
This coin is not a match for the 105. The 105 is shifted farther than C-B-D's coin, has a heavier upper loop, and a visible bottom loop. I don't know what the other die markers are, but just looking at the mintmark I don't think it's a match. But, if you bring it to FUN, Gerry Fortin always has a table there.
You could just email Gerry and ask him directly. Send him the pictures. https://www.seateddimevarieties.com/index.htm gerry@seateddimevarieties.com He lives in Maine, by the way. Just a bit of trivia for you.