Thank you for the quick response and new photos!
very interesting!
Unfortunately, I can not help you in determining the individual pictured ...
Obviously, he could be a brother, because I know that was painted a portrait of "Bob." Rob. "Leander in African dress" in 1901. And where are living heirs of the collection? and who is the GM Dolukhanov?
You can also write me directly at
mag306@rambler.ru