FWIW, J. Stevens A & T Co. made a number of different hammer double barrel models.
The first was the three-trigger model in the 1800s.
In 1902 they made the sidelock/hammer No. 250.
By 1906 they were making mono-blocs - the boxlock No. 225; and a rotary-bolt sidelock double in four grades:
the No. 250 with high pressure steel tubes;
the No. 260 with Twist tubes;
the No. 270 with Damascus tubes; &
the No. 280 with Krupp Fluid Steel tubes
By the next catalogue after 1906, J. Stevens A & T Co. had changed their method of barrel manufacture to "chopper lump", making the boxlock gun the No. 235; and the sidelock guns the No. 255 (high pressure steel barrels) and the No. 265 (Krupp Fluid Steel barrels).
The hammer doubles offerings remained the same in the 1911, 1912, and 1913 catalogues.
J. Stevens A & T Co.'s final catalogue, No. 54, saw the addition of a lower priced hammer double, the No. 215, marketed under the Riverside Arms Co. name.
.