Bull’s Head Can Opener

Q:  I’ve seen several of these can openers in the past, but they were always made in three pieces, with the main body and a replaceable blade held together by some type of bolt, screw or fastener. This is a solid piece with no screw on the side for blade replacement. When I used a magnet on the metal, the body had a lower attraction to the magnet than the blade. The blade might be steel. Can you tell me anything about it?