Hi,
Here are my best guesses of the 4 wheel passenger cars.
Smoker:
Mail/Baggage:
If I recall correctly, in the 1870s, women did not smoke in public or at all. From this assumption, I thought there should be a coach that would be separate from a smoker. Using general dimensions of the Smoker and eliminating the center door, I came up with a plausible coach:
Doug vV