MaxB wrote:
Passing Hither Green DD today I noticed a big sign in EWS colours
saying "73C". If memory serves, this is the old shed code (sub shed
of Stewarts Lane?). Are these numbers still being used or is just a
bit of historical decoration, does anyone know.

Historical decoration. The alphanumeric codes were replaced in 1973, since
when Hither Green has been HG. A lot of depots have customised some of their
locos with traditional cast (or plastic) shedplates, carrying the original
codes.