members of the class had cast-iron numberplates and gilt 'Southern' plates on the tender, but these were subsequently replaced by transfers. British Railways After nationalisation in 1948, the locomotives' initial livery was a slightly modified Southern malachite green livery, where "British Railways" replaced "Southern" in Sunshine Yellow lettering on the tender sides. The Bulleid numbering system was temporarily retained, with an additional "S" prefix, such as S21C1. A short-lived second livery was an experimental purple with red lining, as applied to 35024 East Asiatic Company. This was replaced by British Railways express passenger blue with black and white lining. From 1952, the locomotives carried the standard British Railways Brunswick green livery with orange and black lining and the British Railways crest on the tender tank sides. This livery was perpetuated after rebuilding. Operational assessment The class in both as-built and modified forms has been subject to a range of divergent opinions. The utilisation of welded steel construction and the various innovations that had not previously been seen in British locomotive design meant that the class earned Bulleid the title "Last Giant of Steam". The constant concern for ease of maintenance and utility had not previously been seen on locomotives of older design, whilst their highly efficient boilers represented the ultimate in British steam technology, the hallmark of a successful locomotive design. Despite this, the number of innovations introduced at the same time made the class unreliable and difficult to maintain during the first few years of service. Many of these difficulties were overcome during the rebuilding, leading to D.L. Bradley's statement that the modified locomotives were "the finest express locomotives to work in the country". Overall, the class was largely successful, with half of the locomotives completing more than 1 million miles in revenue-earning service. Models Makers of models of Merchant Navy locomotives include Hornby Railways, Graham Farish and Minitrix. The first OO gauge model of an as-built locomotive was produced by Graham Farish in 1950 followed by Hornby/Wrenn in 1962 and by the modified version. Hornby and Graham Farish currently produce the rebuilt version of the class in OO gauge and N gauge respectively. The Hornby model was introduced in the 2000 edition of the Hornby catalogue. As of December 2010, fifteen members of the class have been produced. In March 2015, Hornby announced the inclusion of a new as-built version of the class in OO gauge in their