American Models rolling stock and locomotives are great running and affordable S scale models available either with scale or high-rail wheels and choice of couplers. One recent comment elsewhere was that there was little distinction between models other than paint schemes. The example was the AM bay window caboose that, in real life, had many variations from railroad to railroad. While some modelers have been clever and skilled enough to alter and relocate windows to match a particular road's caboose, I found that adding different details missing from the stock model could make distinct and more prototypical differences. Hand rails, chains, rear lighting, and other slight modifications make a Great Northern version look different from a Nickel Plate version despite the fact that they are the same stock model. (AM does not offer a Nickel Plate version, but I needed one for the recent American Flyer Berkshire Lionel offered.)
Terry O'Kelly