Nice. That is a bit nicer than the others I've seen. Unusual that the engraver put the quail on the left side between the pins, but the snipe/woodcock on the right side above and in front of the front pin.
My gun serial number 63 only has two patent dates Aug 7, 1883 (No. 282,429), & July 17, 1888 (No. 386,174), and three screws in the trigger plate.
63 05 12-ga American Arms Co. Whitmore left.jpg
63 08 Patent Dates.jpg
By serial number 421, there is a third patent date July 29, 1890 (No. 433,262), and a fourth screw in the trigger plate.
421 01 right.jpg
421 02 Bottom.jpg
Serial number 643 is perfectly plain with no engraving and Twist barrels.
643 03.jpg
My gun has a plain checkered butt plate. By 421 they were using the Bluffton, Ala. butt plates, even though on the ribs they are still marked BOSTON.
421 04 butt plate.jpg
643 09.jpg