The bridle is missing. You see the extra hole, behind the hammer, that's where the bridle screw would go. The boss on the tumbler, also fits in the bridle. And the screw, thru the sear, also goes through the bridle. The fly would be on the back side of the tumbler, and I can't see if it's there or not. Parts are missing---such as bridle plate, bridle screw, and possibly the fly. If you took the hammer off, the tumbler, would fall right out of the lock.