I have about 14 MDC 50' passenger car kits. Some have the duckbill style roof and others the later clerestory style roof. I wonder if anyone knows if both styles of roofs would have the roof vents and stove pipes. Same for full size preserved wood passenger car of near the same length.
The duckbill was essentially a style variation of the basic "bull nose" style clerestory roof. The duckbillfell out of favor, but coexisted with more standard designs before then. For both, the side windows in the clerestory opened inward to provide basic ventilation. This left the roofs relatively "slick." Later , a variety of vents came into use to supplement the ventilation via clerestory windows, especially after metal began replacing wood as the primary material in car constructon.
Duckbill roofs largely fell out of fashion before those changes took place, passing them by.
Wherever there was heat from stoves, you have the stove vents through the roof somehow. This tended to be near the ends of the carbody, but some were located more centrally.
Past general statements, it's always best to find a pic of the prototype to work from.
Mike Lehman
Urbana, IL