December 21 in Paris will be Russian auction auction house Cazeau (Cazo).
There is now an expert Tatiana Barysheva, pushed out of Thuja.
Dominated by Russian books, but there are fine art.
http://www.cazo.fr/
I wonder what they think friends of the portrait, attributed to Petrov-Vodkin, occurring from the collection of S. Schuster?
(He is on the first page of theirs site).
Here it is: