The "War Bonds" 3 pack features three uniqure and prototypically accurate cars produced by Swift Refreigerator Line and Pennsylvania Railroad to promote the purchase of war bonds.  Pennsylvania added the "Buy War Bonds" to hundreds of their cars to support the war effort.  Swift had a similar slogan "Buy More War Bonds", but created a much more elaborate scheme sporting red, white and blue bands that wrap all the way around the car and hold a large "V" for victory on the car door.