I scoured through 1700 "schraubenschlussel" listings on ebay.de and found a half a dozen matches, but not a one with markings that offered any clues.
Best guess is that "E L" is somebody/something and my guess would be northern Europe: Germany/Poland. The French also manufactured this style, but the examples I saw were more diminutive than the OP's specimen.
This is another one where nomenclature gets in the way. I'm actually not sure I'm using the correct term.
<edit> ... and from those I looked at, they were clearly employed as hammers.