In the early 1990's one of the two preserved 'Warships' No. D821 Greyhound was returned to one of the very first versions of the rail blue livery. With the introduction of the then new colour scheme the BRB insisted on strict uniformity between the classes with two bodyside numbers and two cabside emblems (with three different lengths available) on either side of the locomotives (see also here). Clearly, with certain designs, this did not work well, as can be seen above. In the end the Board had to relent, and in the case of the Warships a central smaller emblem was agreed on with cabside numbers.
(Photo from the Alan Ramsay collection)