Seeking Tkachev Sergei Petrovich

[vyadem]

Can you please tell how to contact Tkachev Sergei Petrovich?
Unfortunately, I do not know how he was, but hope is alive and well.
This is what it is preparing a book about one artist. It turns out they studied together in the Vitebsk Art School (School) 1938 /1941. There is a photograph of their course. But unfortunately, the artist almost blind and could not identify anyone.
If someone can help show the photograph Sergei Petrovich would be very grateful!