This remarkable half-hour film was recently shared on the WW2 Civil Defence Re-enactors Facebook page. It's a fantastic film with emphasis on the Messenger Service but it's great for spotting all sorts of insignia and uniform items. Look out for the various ways the 'W' on helmets is painted, look out for Fire Guard armband and sleeve insignia, check out the helmet on the Home Guard, and look at the background posters. Well worth watching.
Watch "The Message Must Get through"
News about interesting insignia, ARP related info and period photos that turn up.