Daryl, there are no markings on the barrel extension of George T. Abbey #46. Only markings are: George T. Abbey on the lock plates and "George T. Abbey, Chicago. Fine Laminated Steel" on the rib, Kilby stamped in block letters on the barrels. #46 and #47 use Abbey's patent rising bite #87814 (U.S.) and #2218 (England). Birmingham view and proof marks. No evidence of Lindner influence. Possibly assembled by Thomas Kilby from action sourced from W&C Scott or I Hollis & Son's, with a nod towards W&C Scott. Date: 1869 to 1872. I checked my Boss using the Purdey bolt and 2'nd patent thumb lever. There are no patent usage markings on the action flats. If #46 and #47 patent marks refer to the use of a Purdey patent, it does not show up on the Boss made approximately the same time period. If not a Purdey patent usage mark, still a interesting bit to explore. Have really enjoyed our discussion so far. Very interesting nice old guns.