Diamond Arms was a trade name used Shapleigh Hardware for guns that were actually made by Iver Johnson of Fitchburg, MA, c. 1920-1950. These were utility guns.
Prior to WWI Diamond Arms shotguns were Belgian imports. They would bring about the same prices, but strictly as mantle decorations. These are unlikely to be 410's.
If it is a single shot it was probably manufactured by Iver Johnson Arms & Cycle works of Fitchburg, MA c. 1920-30's and would be worth $75 or less. If it is a double barrel, it is more likely to be by Crescent Firearms of Meriden, CT, c. 1893-1930 or J. Stevens Arms of Chicopee Falls, MA c. 1930-40. Value of a double may be $125-$200.
Apparently .410's are getting popular with both shooters and collectors, so you may be able to double those prices.AnswerWhat is the value of a 12 gauge (single shot) shotgun? The inscription on the receiver states; "Diamond Arms Company St. Louis"? Based on what we know, the shotgun is more than 75 years old. AnswerYour answer is directly above your question. A single shot 12 gauge may be worth up to $75. AnswerDiamond Arms shotguns were made by Iver Johnson Arms and Cycle Works for Shapleigh Hardware Company of St. Louis, Missouri c. 1900-1930.
Retail value is $75 or less.AnswerMost utility single shots go for $75 or less, but a .410 may bring as much as $150. However, this model was made for about 5 years on either side of the introduction of the 3" .410 shell, so if you are thinking of shooting it, have the chambers measured first.
$150 is a fair price for a .410 model. Mine was a full choke; circa 1934, no serial number.