Looks pretty normal to me. You do know that it is 40% silver right?
it is most likely polished.They made a SMS in 1968?
This. SMS were only '65-'67 and all had no mintmark.Special mint sets were produced by the mint in 1965, 1966, and 1967. Proof and mint sets returned to production in 1968. Data found in the 2015 Red Book.