old Diamond Arms found in abandond house

[Dukindad]

Hi, Friends of mine found an old Diamond Arms 12 ga shot gun in an old abandond house on property they recently acquired. It is in very poor condition and they would like to know the history of the maker, and how old this shot gun is. It is a single barrel, with a serial number. How can I look up the serial number? I can't find much information, but what I did find was on Wikipedia. Can anyone help us?
Dukindad

[Mooseman684]

This is one of a genre of stoutly-built single shots introduced at the inception of smokeless powder around 1900. This was likely built by either Iver Johnson or Savage Arms, but may have been an independent company.
Not much info available...Not very valuable in poor condition...
less than 100.00 .
Does it say "Diamond Arms, St. Louis, Mo., visible on the receiver’s side "?
Rich