The Riverside Arms Co. name first appears in the J. Stevens Arms & Tool Co., Chicopee Falls, Mass., catalogue No. 54 issued circa 1914 on a hammerless double the No. 315 and a hammer double No. 215. These guns were based on G.S. Lewis Patents No. 1,086,378 granted Feb. 10, 1914, for the hammer gun and Patent No. 1,136,247 granted Apr. 20, 1915, for the hammerless gun. During WW-I the Stevens factories were taken over by, I believe New England Westinghouse, for wartime production. After the Great War the Chicopee Falls factories were bought by Savage Arms Corp. and the gun business there emerged as J. Stevens Arms Co. a wholly owned subsidiary of Savage Arms Corp. They continued to manufacture both Stevens and Riverside guns up to about 1930, when they changed the name of their lower priced line from Riverside Arms Co. to Springfield Arms Co. Originally offered in 12- and 16-gauges, the 20-gauge and .410-bore were added to the No. 315 by the 1925 J. Stevens Arms Co. catalogue No. 56. The hammer gun now the Springfield No. 215 was still offered in the 1931 price list, but by the 1933 price list the hammer gun was gone. In the 1933 price list, a cheaper version of the Springfield No. 315 was added to the line with an uncheckered walnut-finish stock and called the Springfield No. 311. Both the No. 315 and the No. 311 remained in the line to WW-II. By 1947, Savage consolidated their operations at Chicopee Falls, Mass. while their factory at Utica, New York went to making washing machines for the post-war housing boom. By the 1947 catalogue the Springfield No. 311 was now a cheaper version for the Fox Model B action with a Tentite stock and forearm. By the 1948 catalogue the Springfield name wasn't being used and the same gun was a Stevens No. 311.
Probably a lot more info then anybody wanted!! Here is the listing from the 1925 J. Stevens Arms Co. catalogue No. 56 --