The 1883 had relatively small, circular brass vents, was available in black or drab, and had two rows of stitching around the edge of the brim. The M.1899 had larger, blackened aluminum vents, was rarely other than drab color, had three rows of stitching around the edge of the brim, and often aluminum or composition spacers between the sweatband and the hat's body to improve air circulation for the wearer's head. Only regulation until 1902 (when a pattern of ventilation holes punched into the hat's crown in the shape of a star was adopted), survivors are rare. Heck, ALL those pre-1911 campaign hats are rare. I'll try to post pictures tonight.
This hat allegedly belonged to one Sheffield Clark. With the hat came a photo of him in what appears to be a species of M.1898 uniform, all drab but for the pointed cuffs, which are lighter in color and thus may be yellow. Family history asserts he was murdered by "a madman" in New Orleans.