Hmmm... the back of the bolt resembles your photo. It has 17159 "electric penciled" on the side of the bolt. The receiver is in the white & I cannot make out any markings. Removing the bolt (looking down into the receiver) exposes a metal plate secured with three screws; stamped "D 28315". The barrel just ahead of the receiver is stamped "LONG RIFLE CART'GE ONLY".