Venice (?), GS monogram (?)

[AlexSpb]

Canvas , about 45õ30 , the beginning of the 20th century.
I assume that some sort of a sin foreign shaped as letters can be confused with the Russian , but here seems to be - clear , " GS "
Besides , the thing comes from a decent local homes, not some Mokritsky of my previous threads on the European garbage bought !
Always considered myself a relatively decent man , not inclined to parasitize erudition respected members of the forum . So honestly did the only thing that prompted weakened accordingly elderly living brains - delved published on our list of 11 pages of Russian artists starting with "W ". As expected , without success. That is, the matching time heels " GS " , of course, is found. But even with a small fraction of the credibility of some of them associate with Venice , I could not .
So , I admit that at an impasse in his research and asking for help to the educated sensible people.
P.S. I think it is unnecessary to remind that the purely theoretical interest in me will never happen - something to be sold !