John Hilton, Judge of the Course at Newmarket; John Fuller, Clerk of the Course; and John Stevens Benjamin Marshall (1768-1835)

The picture has something of this: lid, people, man, cowboy, cavalry, cowman, wear, veil, group, cowboy hat, elderly, weapon, gun, woman, cowgirl, herder, saddle.
Perhaps it’s a painting of two men on horseback shaking hands with a man in a top hat and.