With Castle 5056 behind, I suspect it is March 1962 immediately before re-allocation to Stafford Road.

Peter Kerslake says " This view of 6012 King Edward VI is after early 1958 as the engine has its double chimney and new front frames, both of which were fitted in February 1958. 6012 was still at Old Oak Common and did not go to Stafford Road until April 1962, where it was condemned in September 1962."