Stop Press Girl (1949, Sally Anne Howes, Gordon Jackson, Basil Radford)

Our heroine steps off a broken down bus and walks the rest of the way. There's a comedic scene while the driver tries to restart the bus; it's ST228 (GJ7957), new in 1930 with an LGOC body and last used on Country Area services before being withdrawn.
Actually, the bus she steps off is ST467 (GK3091), which was new in 1930 with a Strachan body and had served with the Olympics Special Events fleet before being withdrawn:
She stops at the front of ST228 before moving on:
There are London street scenes featuring STLs and an ST:
This halfcab saloon is too far away to identify:
Also featured is AEC Regal T508 (ELP232), a 1938 Green Line coach of London Transport, which was at the time newly overhauled. (thanks Colin Read)