Well, yes. The RS-2 was owned by many railroads, including my favorites Gulf, Mobile and Ohio and the New York Central. They look almost identical to the RS-3 - they differ around the battery boxes (lower cab) and the fuel filler location (also around the lower cab). It would take few tooling changes (or just some pleasant modeling work) to turn a RS-3 into a RS-2. Not much difference, but still never modeled in 3RO.
Wikipedia:
The ALCO RS-2 is a 1,500–1,600 horsepower (1,100–1,200 kW) B-B road switcher diesel-electric locomotive built by the American Locomotive Company (ALCO) from 1946 to 1950. ALCO introduced the model after World War II as an improvement on the ALCO RS-1. The locomotive was one of several road switchers in a crowded market, including the Baldwin DRS-4-4-1500, EMD GP7, and FM H-15-44. ALCO discontinued the RS-2 in 1950 in favor of the ALCO RS-3. Several examples have been preserved.
383 locomotives were produced — 374 by the American Locomotive Company, and 9 by Montreal Locomotive Works in Canada. Eight of the ALCO RS-2s were exported to Canada. The RS-2 has a single, 12 cylinder, model 244B engine, developing 1,500 horsepower (1,100 kW). Thirty-one locomotives built by Alco between February and May 1950 with the 12 cylinder 244C 1,600 horsepower (1,200 kW) engine.