This is the real McCoy, no fake identities here. This Mitchell started life as 44-31258 with the USAAF, but was immediately delivered to the Netherlands East Indies Air Force in Sep 1945 as N5-264, which was changed to M-464 in June 1947. In Jun 1950 it was transferred to the Indonesian AF, and after serving with them for many years (using the same serial M-464) it arrived at the museum in Oct 1971.
In reality this is 43-31171 but is on display at the IWM Duxford to represent B-25J 43-4064 that served with the 488th BS, 340th BG, 12th Air Force in the latter stages of the Second World War from its base in Corsica. This was the BG that formed the inspiration for Joseph Heller's satirical novel Catch-22. Heller served as a bombardier in the 488th Bomb Squadron and had extensive experience flying bombing missions in Mitchells.