single barrel was probably an Iver Johnson. There were double barrel models made probably by Iver Johnson and possibly Stevens. They were made under contract after WWI for Sharpliegh Hardware in St Louis. This was common practice as Iver Johnson would put your Company name or logo or P/N on anything they made . Iver Johnson originally made bicycles and merged into firearms. Their Champion guns were sold with as many as 20+ different names on them. I have 6 different guns and they all resemble each other very much. Am looking for an extractor for a 12 gague single Champion.
50-100 USD
20-120 usd
50-100
Seldom exceed 150 USD
70-100 years
You have already identified it as a Shapleigh's King Nitro. Shapleigh Hardware was in St Louis Missouri from the mid 19th century until the middle of the 20th. Their King Nitro guns were manufactured by W.H. Davenport and later by Stevens/Savage.
50-100 USD
BLue Book of Gun Values
50-100 or so
Follow the link to the related question.
I believe that King Nitro was a model name of Shapleigh Arms Co, St. Louis, MO.
Single barrel, tops out at $75. Double-barrel, tops out at $175. sales@countrygunsmith.net