A wonderful short instructional film from 1972 on how to get the best use out of your telephone in a work situation and not, as happens in the opening minute, the phone making you so enraged that you end up shooting it (which lets face it, isn't very British!)
The film covers basic phone etiquette (which is mostly about just being polite, something a lot of people still need to learn). The film includes a whole host of GPO 746 dial phones though also look out for a cheeky pair of trimphones too. It is a wonderful little slice of the early 1970s British office life. Look out for Leslie Schofield in the workshop.