In 1879, the mint used two different S mint marks, one small, and one larger on the Morgan dollar. Any one ever heard of a 1879-S/S Morgan, large over small MM ?
Not in Breen's. But, looks like VAM-15, listed as 'doubled S.' check to see if the 1 in the date is doubled.
79-s/s yes the one is doubled. a notch on the nose and clear doubling just under the nose, and a notch on the left foot, and something on top of the left foot. I think VAM 15 is a 1900-O.
Bone Head, If enough Varieties are found for each Date and Mint in the Morgan and/or Peace Dollar Series, then they all could have a VAM-15! There is a VAM-15 for the 1900-O Morgan but it has no relevance to the VAM-15 for the 1879-S Morgan, so Treashunt was correct. Your' coin appears to be a 1879-S "VAM-15" Morgan Dollar with "S" over "S" Mint mark and doubled "1" and "8" in the Date! Frank