Dickey's GAH win was in 1896, and as Bill observed he was a major gun dealer and rep for the United States Cartridge Co.
https://digital.la84.org/digital/col...oll17/id/47169
O.R. Dickey, of Boston. Mass., winner, used a very handsome Parker Bros. hammerless gun, of the pigeon model, and his load consisted of 50 grains, or about 3 1/2 drams by measure, of American “E.C.” powder, 1 trap wad, one 3/8 inch pink felt, one 1/4-inch pink edge, and 1 1/8 ounce of No. 7 chilled shot in the United States Cartridge Co.'s “Rapid” shells, 2 3/4 inches in length.
He was still shooting as a Professional in 1915
https://digital.la84.org/digital/col.../22374/rec/265