The Hunter Arms 'Trap Gun' buttplate is commonly found on pre-1913 O and OO Grades. No "Trap Gun" was advertised in the pre-1913 catalogs, and the buttplate was likely a marketing tool to promote Smith guns for the increasingly popular sport of trap shooting. Shooters using L.C. Smith guns took first, second, and third places at the Grand American Handicap in 1902.

You might enjoy some of the ads on the 'Trap and Skeet Guns' album
http://www.picturetrail.com/gallery.fcgi?p=999&gid=17127707Unfortunately, there are some gaps in the serial number records and your's is not listed
http://www.lcsmith.org/shotguns/manufacture.html