the value of a 1948 Stevens double barrel shotgun 16 gauge. Hammerless.
1910, give or take a few years.
The Model 215, a hammer gun, and the model 315, a hammerless
The name with "Tool Co" at the end was only used from 1887 - 1916.
Barrels have been cut down. 100-175 USD
If the model number isn't marked somewhere on the gun, it's pretty hard to determine exactly which Stevens double you have since they made at least 60 different models in three basic configurations - side hammer, back hammer, and hammerless. I can tell you that the "arms & tool" version of the company name was used from 1886 to 1916. If has a hammerless boxlock action, it was made after 1903.
If that date is Apr 20, 1915, the gun is a J. Stevens Arms Co Model 311 hammerless.
Single barrel, $50-$75. Double, $150-$250.
Many gunsmiths will have one or two in the back room, or you can order from Numrich Gun Parts at the related link.
The value of any firearm is based on exact make, model and condition. You need a hands-on assessment to give you an actual value- anywhere from $100 to $600 at a guess. There were dozens of different models of Stevens side by side hammerless guns. Sorry-
Hibbard Spencer Bartlett & Co sold guns with the Newport name as early as the 1880s, but a hammerless Newport double would have been made by either Crescent between 1903 and 1930 or Stevens after that. The HSB trade names were discontinued during or shortly after World War 2.