I know exactly how you feel.
How could someone make such a beautiful piece and only stamp "800" on it? I have found a few pieces with only an "800" or a "900" with an initial or two, and the best we could come up with is to describe it as "Continental." Somewhere in the continent of Europe, at some point from 1880-1920, would be my guess.
Remember that in Belgium, hallmarking was not compulsory during this period, so whenever I find a mystery piece such as this, I always keep Belgium as a distinct possibility. It's always great to find a real piece of Belgium silver, for example by Wolfers or Delheid Freres, but let's get back on track...
If this were German, I believe, and correct me if I am wrong, that the one city of Hanau in Germany was exempt from the traditional German hallmarking system, so you sometimes find pieces of "Hanau Silver" which has a wide range of different kinds of marks, many of which seem decorative in nature and some of which make no sense whatsoever. Hanau Silver was very often 800 purity.
So why couldn't this be a piece of Hanau silver?