Thank you for the replies. So the 1960 stock, apart from the later ones used on the Ongar branch, was all unpainted aluminium, right?
Yes. The two red units (3906 and 3908) were painted as a heritage attempt some time around the late 1980s/early 1990s. The 1960 stock motor cars were originally built as unpainted.
Of course, the Standard stock, and later 1938 stock, trailers were painted to match DM cars as far as possible. One such unit (3902 if I remember rightly) reached as the 1990s in this condition, but by this time was being used for spares and was eventually scrapped.
Yes but ... The 1960 stock cars themselves (all DM) were delivered unpainted and stayed that way until four of them (2 units, including trailers) were painted red in 1990. Two DMs also became part of the Track Recording Train (with a 1973 stock trailer) and were painted in a special livery, since modified to something more corporate.
The original trailers were pre-'38 standard stock (red) and were repainted silver to 'match' the unpainted DMs. It was a poor match. In the late 70s/early 80s these worn out trailers were replaced with 1938 stick trailers repainted in a 'modified silver' (aka white) in another attempt to match the unpainted DMs. Perhaps they should have painted the DMs white at that time to match the trailers