The rebuilds which took place in 1942 when two 'Jubilees' were given a modified version of the new and larger No.2 taper boiler which had been fitted to No.6170 British Legion with such good effect. Nos 5735/6 Comet and Phoenix were chosen, though we do not know why. It might have been because it was a simple way of getting two more boilers into the 'spare' pool during the war. The engines were transformed overnight into two of the most outstanding machines owned by the LMS and they undoubtadly formed the launch pad from which sprang the major rebuilding of the 'Royal Scots' and some of the 'Patriots'. No further rebuilding of the 'jubilees' took place nor was it ever seriously contemplated. The fact that this significnat move forward began with the modern three-cylinder engines rather than the older parallel boiler 'Scots' or 'Patriots' was probably to minimise the work content during wartime. The inspiration behind the move was that of Coleman who, having solved the main problem of the 'Jubilees' draughting, felt that a still more radical change might effect even more improvement. Once it has been realised what was possible then it certainly made more sense to take the 'Scots' and 'Patriots' in hand , leeving the 'Jubilees', as they were. The two rebuilds were never multiplied and were only augmented in 1946 when the above mentioned 'Patriot' rebuilding began. The two rebuilt types were all but identical in cylinder and other dimensional critiria and could scarce be told apart from the outside. Like the 'Patriots', Nos. 5735/6 were also fitted with 'Royal Scot' pattern smoke deflectors in BR days.