One outstanding source of railway film that deserves mention is the British Transport Film Unit, which was set up after the nationalisation of the railways partly to promote business but also to raise people's spirits in that very hard time of austerity. Most of the films were documentary in character, but the technical quality is outstanding, as is so much of the content of the films. The film unit continued in a high profile way (with a massive budget) through the 1950s, but the tory government in the early 1960s soon cut that. The unit continued from hand to mouth into the very early 1970s at least. Working as an architect for the railways I had a few things to do with them, on projects like Sheffield Tinsley Marshalling Yard (1964) and the last was in 1971 or 1972 on the reconstruction of London Bridge Station.
You can often see old BTF footage on television. Last night for example there was ten minutes with John Betjamin on BBC Channel 4 TV at 7.00.
On a different theme, I was a student when the 'Titfield Thunderbolt' film came out in 1953. I was also Publicity Officer of the Midland Area of the Railway Development Association, and we arranged to do a deal with the manager of the Odeon (I think) cinema at Sutton, to put up a display pressing for better service on the Sutton line, with more frequent trains, diesel rather than steam and a new station at Butlers Lane. This was part of a wider campaign which received a lot of support from MPs and local councils and eventually we got all we asked for - very much like the Titfield Thunderbolt story!
Peter