IMO it is a German brand (could have sold elseware I suppose), I have a link to a gas pump site in Germany and the DEA is spelled out Deutche Erd÷l AG, wich means something like "German Earth Oil LTD".
Please check www.alte-tanksaeulen.de and you will find many nice pictures of Gilbarco-Schwelm pumps restored to DEA brand - and also lots of other nice pumps :-)
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Claes