My dad is looking at buying a mint condition smith & wesson 1000m waterfowler shotgun for only $200, but apparently it is missing the restrictor pin that limits the magazine to 3 rounds. Any gun gurus here know where he might be able to get a hold of this part? Anybody know much about these in general. I got to handle it and it seems like a well balanced, light shotgun. Another question while I'm at it... Any other barrels that it will accept? It has a fixed full choke but wondering if you can buy a barrel that accepts choke tubes.