There were seveal variations of the "Flues" period single barrel trap guns, starting around 1915 or so. They are probably more "artistic" than the later Knick [for Knickerbocker] models produced much later. The Knick models seem to be mechanically superior----------oh, sort of like the NID models seem mechanically better than the Flues, Crass, Minier [sp?], etc. But if your are not going to shoot lots of shells, the earlier guns are quite nice and better engraved.