I got in a single barrel shotgun yesterday that needs a hammer spring and retaining screw and also tang screw. The gun has no manufactors name on it. It has [KK] on the left side of the receiver and patent dates on the right side. Dec15 91 Aug11 96 Aug14 00 May27 02. The gun has a takedown screw that has large circle attached to it that flips up out of a cut out in the receiver that you use to remove the screw instead of a screwdriver. The trigger guard has an intergral screw on the front of the guard and a screw at the rear like a double barrel shotgun trigger guard. The fore end comes off by removing one screw. The fore end iron is held on by one screw through the barrel lug. They are not screwed together like most single barrels. At first glance it looks like an Iver Johnson except it has an open tang like a Marlin 336 instead of one long stock bolt. There is a serial # on it. And the number 12 on the barrel just ahead of the fore end on the bottom. It also uses a screw to hold the hammer in place instead of a pin. I hope that is enough info.Thanks.