At Chatham Militaria Fair today I met a seller with the badge below. It was claimed the badge was issued to Merchant Seamen working on Civil Defence duties in the London area. However, the badge (with an ARP pattern number of 186) was issued to Merchant Seaman who had lost their kit when their previous ship was lost. It was sewn onto the left breast pocket of the harder wearing Rescue Battledress. The seamen were not on any Civil Defence duties.
News about interesting insignia, ARP related info and period photos that turn up.