73155 1957c Ruislip troughs Down Master Cutler
This image was recorded as 15th June 1956 but the loco was not released new from Doncaster Works until 19th December 1956, arriving at Neasden on 4th January. It is clearly high summer so I suspect the quoted date is exacly a year out. It moved to the Midland at Millhouses in May 1958 so it was only a GC section engine for a short period.