Dave Snow made a Plymouth switcher reskinned in multiple variations that is really nice. It's a great addition for wharves, grain silos, and industrial lines. There is a Davenport available on the DLS, but I can't remember who made it. Ben Dorsey made some Baldwin switchers, I think, or at least it might be a Whitcomb, however, that's a 3-ft narrow gauge model. I've never seen a boxcab Alco switcher, however, there is a CNR Boxcab available on the DLS. This is for the Port Stanley line up there on the Great Lakes.
I hope these are helpful. Dave's little Plymouths have found their home on my routes as they chug nicely and look really cool switching overly-large grain hoppers and boxcars compared to their smaller size.
John