This factory manufactured rear trigger plate screw is for the Iver Johnson Sporting Goods Co. Knox - All hammerless double shotgun in 12 gauge and is in very good condition exhibiting a grayish brown patina with light wear.   This screw fits the late variation trigger plate assembly.  (file photo)

Note: Iver Johnson shotguns with the following serial numbers have been observed with this part:

12 gauge: 184436

 20 gauge: 75043