Rather tired comedy that wouldn't appeal today and not as funny as the TV series it was based on (I have one on DVD and it's better than this). Arthur Howard as the put-upon Deputy Head Pettigrew was as always very good though.
Interesting nonetheless if only to see a young Richard Briers and yet again Melvin Hayes (at 24) playing a schoolboy - also sort of "linked" to him was Donald Hewlett, as a teacher, who played the Colonel in It Ain't Half Hot Mum.
ALSO noticed, yet again, that TPTV had blurred out a very brief shot of somebody's nude (Gosh!!) bottom, as they did at the end of the I'm All Right Jack film. Very silly bit of PC control.