If memory serves me correctly this is a remake of the 1937 Will Hay comedy "Good Morning Boys", to which it compares quite favourably. Coming a year before the cycle of St Trinians films began, it, and by default the Will Hay schoolmaster comedies of the thirties from which it derives, can be viewed as serving as a kind of prototype for that series. In any event it seems to me that the St Trinians films have far more in common with this little picture than they do with the far more sophisticated humour of "The Happiest Days of Your Life"(1950) with which they are usually linked.
Although for the most part he is generally forgotten today, I always found Ronald Shiner quite a likable comedy actor, and to be frank, I probably prefer him in this role to Will Hay, who in his guise as schoolmaster could become a little irritating at times. Interestingly I also find him a little reminiscent of Shemp Howard in places. I find it frustrating that I have been able to view so few of the films listed in his filmography.
Other familiar faces notable in the cast are a young Anthony Newley and a young Ronnie Corbett, Mary Jerrold as Mrs Bagshot brings Katie Johnson to mind......and there's also Richard Wattis as ...you guessed it.. a Ministry of Education official.