Please help. I have this .410 and cannot seem to find a real answer on it's origin. The left side has 'Newport' stamped with 'P' inside of a diamond underneath. Beneath the triggerguard has the serial number E 87000 XG. I have read on numerous gun forums and have not found a similiarly marked shotgun. The explanations have ranged from Iver Johnson 'Champion' model to Crescent produced for Hibbard, Spencer, & Bartlett. The barrel is stamped '3 INCH CHAMBER' and there are no other barrel markings. The schematics on gunpartscorp.com for Iver Johnson seem to match?