I'm always on the hunt for rare antique watercolor sets, and, as a lover of miniature things, seem to have a special knack for finding what would be called "toy" watercolor sets, with extra small watercolor blocks. Though there is no maker's mark on this set but It seems to me it must have been made in Germany for the English/American market. The paint blocks show crowns on one side and the other side is embossed ""Feine Malerfabre," meaning fine paint in German. Missing the brush and mixing pots, but the paints are all there but one, and in excellent, unused or nearly so condition. 

6 7/16 x 3 1/8" x 1/2". As noted, pots and brush long gone (though not too hard to replace), paints themselves in excellent condition. The box may be missing an end piece, but it otherwise in excellent condition too. Late 19th c. I would guess.