A rather nice selection of WW2 and Civil Defence relayed armbands are coming up for sale via saleroom.com. There are some of the generic ones for Fire Watcher (F.W.), First Aid Post (F.A.P.) and ARP Warden varieties as well as a rarer National Savings armband. I believe the top middle is a decontamination (DC) armband for a business. A very nice grouping.
News about interesting insignia, ARP related info and period photos that turn up.