BR(E) A1 4-6-2 No 60121 Silurian on shed at Doncaster on 20th May 1950, it has not yet been named but records show this was done at its works visit from which it was released the previous day! There is another photo of it in service at York station on 22nd May with it still spotless and without a name. It re-visited works on 23-26 May for an Unclassified so I suspect the nameplates were actually added then.

Photo: T.G. Hepburn / Rail Archive Stephenson