RINGLING BROS. AND BARNUM & BAILEY™ - 72' SMOOTH-SIDE BAGGAGE GENERATOR CAR #63007 - HO Scale. in the 1930's lighter weight materials allowed for the development and production of a variety of coach, baggage, and observation cars as railroads ushered in the beginning of the streamline era. Materials like stainless steel, and aluminum, allowed for passenger cars to have smooth or fluted sides and smooth roof lines.