When I was a young boy back in the late 1940s, my Dad, Harry L. Hall, would take me with him to downtown Kansas City to visit the Musselman & Hall office. The office was in the old Railway Exchange building on 7th St, between Grand and Walnut. Unfortunately, the building has been razed and replaced by an ugly asphalt parking lot.
The Railway Exchange Building was a beautiful seven story red brick building with a Grand staircase going up the center of the building from the main lobby. I do not remember there being an elevator. There certainly was no air conditioning. Ventilation was provided by a bank of massive windows with no screens.