This seems to me to be the sort of video that everyone with any interest in the subject will have seen, but it's new to me, and I thought it might be worth an airing here.
This was posted on Youtube by Caliver Books a couple of years ago. It looks like a clip from the early 1980s, and it features a brief potted history of (local) Southampton manufacturer Miniature Figurines, followed by a "how to play wargames" section featuring a very young Iain Dickie.
Pick the bits you like; I was impressed by the very weird opening sequence, of lead castings being melted, run backwards (which is satisfyingly surreal, and will be a big hit with all entropy fans), and by the presenter in the end section, Fred Dinenage, whom I vaguely remember as the host of kids' science programmes, including an explain-everything show entitled How?, which ran in various manifestations from 1966 to recent times. Also, of course, Dave Higgs working on 15mm figure masters with a soldering iron is pretty compulsive viewing.
The Bold Fred visits wargaming matters such as "why?" (which is a relative of "How?"), the role of dice in the game and the important issue of how wargamers' wives are likely to be hostile to their hobby.