Thirteen of the O2 Class were rebuilt (to O2/4) by Thompson in 1943 with a 100A (B1 type) boiler. This being slightly shorter than the original, required the smokebox to be extended backwards.
O2/4 No 63962 at Doncaster station in November 1961. It was finally withdrawn in September 1963, being one of 30 (of 67) taken out of service that month.

© David P Williams Archive / Rail-Online
Original photograph by Paul Claxton