Diamond Arms was a trade name used by Shapleigh Hardware Co of St Louis from the late 1800s to about 1950. The guns were made by G. B. Crandall, Harrington & Richardson, Hopkins & Allen Arms, J. Stevens Arms Co, and probably a few others. A 410 single shot is most likely a Stevens product. If that statement about one piece barrel actually says "barrel and lug forged in one piece" it is a Stevens. If it says "barrel and lug forged in one" (exactly the same except no "piece") it is by Iver Johnson Arms and Cycle Works.
The value of a 1905 model D single barrel choke bored Diamond Arms shotgun is actually dependent upon a number of things. Most importantly the condition of the shotgun.
i.have.a.j-reynolds-double barrel 16ga belguim rabbit ear shotgun seaking information
Not enough information
$35-$90, depending on condition.
Single shot: $25 to $75, Double barrel: $100-$200, depending on condition.
About $50-$75 as a mantle decoration.
Have you tired the internet?
Impossible to answer without more information.
Pull off the foregrip by exerting pressure from the front separating the stock from the barrel. Open the shotgun and the barel will separate. Pull down and separate the foregrip from the barrel. It is spring loaded. Open the action and the barrel will separate by lifting it to disengage the tang.
Would need to know the other markings as well.
A shotgun barrel with a cylinder bore choke.
Sold by Sears Roebuck. Probably manufactured by Stevens.