As the train approaches a signal box, it's pulling 12 carriages but there's only 8 in the shot of it going away, and some of them look like ordinary carriages rather than the fully enclosed mail ones.
The train is a night mail train yet some of the shots are in daylight.
The train does not necessarily run solely during night time hours, and additionally, filming was done during the day due to technical difficulties of lighting. This is a matter of artistic license.
The train does not necessarily run solely during night time hours, and additionally, filming was done during the day due to technical difficulties of lighting. This is a matter of artistic license.