I bought this from a collector, it just looked like an interesting old pen. It looks like a 1930 ish lever filler. 
But it appears as if it might be an eye dropper conversion. It has a see through window, a screw on blind cap at the end of the barrel but it also has a press bar ink filler. When you look through the ink window all you see is the aluminium sleeve, not the ink level. I can see no other reason why it has an ink window and a blind cap. The pen fills well and writes o.k. but its really short and awkward to use unless it is in posted mode. It feels solid and fairly well made and the only barrel imprint says 'BROMO', I don't know whether this refers to the maker, the owner, or the seller.
