Among the sample, I picked out these three covers from the publishing house of Abraham Stybel, born in Poland in 1884 died in New York in 1946. His interests included contemporary Russian art and literature and Jewish questions: note the "Art Nouveau" style in which his name and address is printed at top left. I just assume the covers are to his brother but I cannot get a Google fix on that.
Covers to Joachim Stybel are often seen in dealers' boxes and even in auction. The three below nicely illustrate the three Foreign Tariffs which were applied through the period of the Provisional Government and the first year of Soviet power.
I have no mail to America via the Western route after July 1918; most mail after that date goes out from White-controlled areas through Vladivostok.