Those barrels in your picture have the rounded lug as was done in Fulton compared to the squared lug used in Syracuse.
The Trap Gun butt plate used in Syracuse was an advertising ploy. In Syracuse catalogs it stated that these guns were good in the field as well as on the trap line.
The Trap gun butt plate was used on hammerless guns and the hammer guns had a setter with it's right foot on a rock.
In my records starting around 26644 to 29743 most all of these guns had the rounded lug, no makers mark on barrels, narrow convex ribs on receiver, coarser checkering, "V" shaped ebony for-end tip compared to the vase shaped Syracuse for-end. These were from 1890 and again what I call Transition guns.