Since they're currently working on a route set during the steam era in Britain, I would like to see the Texas and Pacific railroad during the transition era from steam to diesel during the late 40s and early 50s. I looked up steam locomotives they had we're 2-10-4 "Texas" type locomotives for hauling freight and 4-8-2 "Mountain" type locomotives for pulling passenger trains, they also had USRA 0-8-0 switchers and for diesels they had emd f7s and I think f3s and they had GP7 diesel switchers and they also had NW2 switchers also and maybe they can add other locomotives as dlcs it's just a thought.
