Help please understand that the picture

[Ketallair]

Dear experts! There are several paintings inherited from his grandfather, who once finished VHUTEMAS. Perhaps it is he himself wrote. But the technology at all varies, so there are doubts about the authorship. I am interested in mainly because the time has come to little podrestavrirovat and podkonservirovat - want to understand how serious the need for this approach.
Here's one: oil, board, approximately 40 x 30, no signature. You can tell exactly what was written before 1940 please tell me what it might be like? Copy? From the perspective of a commercial but artistic - how valuable?
Thanks in advance.
Re-shoot with a tripod, but the point of white led a fairly conventional - I have no natural light in such quantities, alas.