The below helmet is currently on eBay and it's something I have never seen the likes of before. From the images (check out the link to see more) you can make out "Air Raid Helmet" and "Grimsby" with a patent pending number. Perhaps a company hoping to make a few bob on creating a helmet for civilians before the Zuckerman helmet was released in 1941.
UPDATE: I have been informed that a number of companies made a similar style of helmet. See the advert below for the 'Defiance' helmet. Seems a number of these helmets came into production around the time of the Munich Crisis in 1938.
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