Although it's not the most focused photo you'll ever find, the photo below does shows a gentlemen wearing the CD (Civil Defence) blue enamel lapel badge being worn (under magnification it is a CD and not HG badge). No date on the back of photo alas but it is likely to be wartime and the style of jacket lapels fits. Examples of this badge being worn are quite rare. The photograph was obtained from eBay for the princely sum of 50p...
News about interesting insignia, ARP related info and period photos that turn up.