That looks like a pretty nice Grade 1 a Owatonna. As I recall from Topgun's articles, the Grade 1 was dropped fairly early on. The Syracuse Arms Co. guns came in two lines -- the stock guns --

Grade 00 had "Tripplet" steel barrels (added to the line later)
Grade 0 had Twist barrels and no engraving
Grade 1 had Twist barrels and some engraving (dropped from line fairly early)
Grade 2 had Damascus barrels and no engraving
Grade 3 had Damascus barrels and engraving

-- the custom guns --

Grade A
Grade A1 Special
Grade B
Grade C
Grade D

As I recall the first four could have either Damascus or Krupp barrels and the D could have Damascus, Krupp or Whitworth barrels.

Tom can correct my errors or ommissions.