They look great! Having grown up and living the West it is good to see more people around the world care about the local history. (Now if we could get more people who live here now to care about it instead of everything 'worldly' and all the latest mass-marketing ploys...)
Ranting of which - I wish Playmobil would have kept upgrading and revamping the Western line over the years, like they have done with other lines.
Regardless of some of the interesting things that can be done with system-x, Steck really shows itself when you see any custom structures.
Looking at your 'engine shed' (that's what they are called here, instead of a depot (a "depot" here would be a small train station)), one can see that it would have been really neat if Playmobil had made some 'half-height' Steck wall pieces! Personally, I could never cut a Steck piece in half, as used Playmobil here in Canada is hard enough to get. Now, if I lived in Europe where it is plentiful (or had a MacGayver size collection)...
Are you able to set all the buildings up together for a large diorama (and include a train track)?