The No. 215 was a hammer gun. The G.S. Lewis patent No. 1,136,247 granted Apr. 20, 1915, gun was introduced in the J. Stevens Arms & Tool Co.'s last large catalog, General Catalog No. 54, as their lower priced line, Riverside Arms Co., No. 315 in 12- and 16-gauges --
Catalog No. 54, Riverside Arms Co. No. 315.jpeg
J. Stevens Arms & Tool Co. was acquired by New England Westinghouse for war production for The Great War, and was renamed J. Stevens Arms Co. After the war, NEW sold J. Stevens Arms Co. to Savage Arms Corp. which continued to operate it as a separate entity until after WW-II. The Riverside Arms Co. No. 315 continued in the offerings after WW-I and by 1923, they added a slightly upscale version the J. Stevens No. 330 and added the 20-gauge to the offerings --
No. 330 1923.JPG
By 1925 they added a .410-bore version --
Riverside No. 315 from Catalogue No. 56, 1925.jpg
About 1928, J. Stevens Arms Co. changed the name of their low priced line to Springfield Arms Co. For 1929, they added a lower priced version of the G.S. Lewis designed gun, the Springfield No. 311 --
Springfield No. 311 brochure interior.jpg
In addition to these three quality levels of the gun, J. Stevens Arms Co. produced numerous "trade branded" versions of this gun up to WW-II.