Iver Johnson jacketed breech shotgun

Question
Thought you might want to see my barn find. There is absolutely no identification other than SN 2043 and patent date of July 27, 1880 on the ejector lug. That patent was issued to Dexter Smith for an improved ejector. The barrel is 31-3/4" long and is 12 ga. I also saw a reference to the jacketed breech being for heavy loads for hunting fowl. Any additional info would be appreciated. Don

Answer
Hello Don.
  I see you have done some research on your own, and I commend you for it. The information I have is in addition to it. The 'Iver Johnson Arms & Cycle Works Firearms 1871-1993' research work by W.E.Goforth says this: "The earliest patent date to appear on an Iver Johnson shotgun was July 27, 1880. This patent number 230,409 covered a single barrel shotgun with a central mounted hammer and was controlled by J.P.Lovell Co. It was marked on the early model Champions Iver Johnson and Martin Bye manufactured for J.P.Lovell Co.....The Champion Jacketed Breech Single Gun 1912-1917 is the same as Model 36 except for the heavy reinforced breech." There may be an adjustment screw behind the trigger for adjusting the hammer spring and trigger pull.
  If you have your gun approved 'fit to fire' by a licensed and competent gunsmith, it may enjoy many years of service, yet.
  Thank you for asking for me, and allowing me to add to your research. Charles Gage