Spitfire IX BF274 was used for many trials and was originally a Mk V aircraft. It was given an incorrect serial number there were no Spitfires in the BF serial range - and eventually became a T Mk IX trainer sold in Holland.

A Spitfire IX with an early trial installation of four underwing 100lb rocket projectiles, with 60-lb (27-kg) heads.

Three views of Spitfire IX MK753, of which, unusually, no career record appears to have survived.

Former Mk V BS452 pictured after it was converted to Mk IX standard.