Seem to remember this family being mentioned in "Russian Court Memoirs"originally printed by Herbert Jenkins,London in 1917,reprinted in the 1990's.They were descended from one of the 4 younger brothers of Catherine the Greats lover Prince Gregory (the descendants of another brother were the Princes Orlov who died out with the death of Prince Nicholas in 1960's).I seem to remember there was a mention of a Count O-D who was married to a Baroness Teckla DE Staal/ De Stael .They will be mentioned in the volumes of " Comtades de Empire Russe" by Jacques Ferrand.This lists all the Counts and their families from the revolution till the 1970's/80's.