This was one of a number training films which Associated British Pathe made, mostly aimed at the Home Guard. The voice of Bob Danvers Walker, so often a commentator for Pathe.
Roger Corman, who has died aged 98, with a Thompson during the filming of Bloody Mama, based loosely on the Ma Barker story.
The enlarged hole in the end of the Cutts betrays the blank-firing choke incorporated in it.
Pardon Us was a take-off of the Wallace Beery movie The Big House, and the antagonist looks rather similar to Wallace Beery. The same gun, with the rather obvious attachment to make it work with blanks, seems to have been used in both.
I've got one of these. They are usually rather tight fit. They come in 'magazine fitted' and 'no magazine' varieties and the stock system does not appear to have differentiated between them.