I picked up a #1 mk111 forearm I assumed it was a reproduction but found some stamps which two I haven’t any idea what they are. The broad arrow I know. I have seen the crown 2a but don’t know who uses it. The belt buckle looking one I haven’t seen before. The three stamps are located about 1 1/2” behind the nose piece. I either bought a reproduction which someone stamped or an unissued original stock.