Due to the Korean War, USAF serials ran into five digits for the 1951 and 1952 fiscal years. Plenty of Twin Beech aircraft had been built during WWII, of course, and the 900 C-45Gs and C-45Hs were in fact remanufactured machines. This one used to be 42-37534, an AT-11. Later sold on civilian market as N87688.