Not sure if it's been mentioned already but there is Terror on a Train 1953, also known as Time Bomb depending on which country were are in, with Glenn Ford, Maurice Denholm, Victor Maddern and numerous other common faces of British films. Which featured BR 8F
Ghost Ship 1952 with Dermot Walsh, Hugh Burden & Hazel Court and a short appearance of Ian Carmichael. Featuring several shots of 2 car Southern Electrics...still bearing Southern lettering I think. I have done some screen shots so will try to find and post them.
On the Arthur Askey front, alongside The Ghost Train, there is also The Love Match when, if I remember, he pinches a Midland 4F 0-6-0 and it's train so he can get to a football match.
I do remember there being several railway lines shown in Carry on Constable...don't remember any trains but several sound effects.