Good-Time Girl - Wikipedia

1hr 21mins
Dir: David MacDonald
Starring: Jean Kent and Dennis Price

A young girl gets involved with a criminal gang and heads down the road to ruin

This drama was based on Arthur La Bern’s 1947 novel Night Darkens the Street, and features a scene with Jean Kent boarding a departing Southern Railway EMU at night. The two shots have been lightened by me as they were very dark. They are unlikely to show the same train as film crews have a nasty habit of playing tricks, i.e. Jean boards train at one station, then cut to a stock shot of a departing train from somewhere else! In addition to this, we see nothing of the station at all.

By no means the clearest shot in the world but this is Jean Kent boarding a Southern Railway EMU.
The motorman (vintage term for drivers of electric multiple unit stock) looks back to check all is well as the train begins to pull away. Although we cannot be sure because we see nothing of the station, this should be London Victoria as headcode 14 is Victoria-Brighton (slow) via Redhill. The general consensus via ‘those in the know’ is that this unit is a Maunsell 4 LAV.