We have placed in the store models of Great Northern 12 panel box cars by InterMountain in five different paint schemes the Great Northern actually used, each with six road numbers. The models are painted: Vermillion red with slanted ‘Great Northern’ to the right of the door, Vermillion red with 'Empire Builder" lettering, Glacier green with 'Empire Builder" lettering, Big Sky Blue, and Pullman Green express box cars that operated in passenger trains.
Great Northern built 4,000 of these 12 panel 40' 6" Inside Length box cars at St Cloud in 1948, 1949 and 1951, 25 of which were express box cars.
When production of the 12 panel box cars ended in 1951, the 3,975 freight cars of this design were 19% of the box car roster. Most of them lasted to and beyond the BN merger. If you are modeling 1950-1970, you should have a significant number of these cars in your fleet.
Cars built until about the middle of 1949 were 10’ Inside Height and provided 3715 cubic feet of space. Cars 18500-19499 and above were 10-2 Inside Height and provided 3775 cubic feet of space. The difference in inside height reflects the presence of an interior ceiling in the 10 foot high cars, and no ceiling in the 10-2 high cars. Exterior dimensions were the same. When built these cars were painted mineral red.
See GNRHS Reference Sheet 61 and Modelers’ Pages 97 and 98.