I remember being extremely thrilled when I watched the movie 'Sink the Bismark.' It was a very gripping story and almost as a cherry on the top; Victor Maddern crops up at the end to groan about the Navy top brass. It gave the movie that special Brit flick seal of approval.
My favorite Victor Maddern film was 'Light up the Sky' in which he had a more prominent role then usual, alongside Tommy Steel, Benny Hill and Johnny Briggs. Again he is grumpy - a Lance Corporal, and in this picture, he gets to groan all the way through the movie. This he does with great aplomb with lines of ironic complaint that are entertaining.
I also remember being surprised when he cropped up in a Patrick Troughton, Doctor Who story called Fury from the Deep. When next watching an old 1950s or 1960s matinee; look out for good old Victor - he is usually having a groan about something.