When I listen to it carefully, I hear :
-a bass voice
-a "vibrato-ish" treble voice (like a double-reeded accordion)
-a "whistley" treble voice , more like an English Concertina.
I wouldn't be surprised if this were concertina, since this instrument was common in Russia at the beginning of the century. By the way, 3 great early American concertinists were Russian by origin : Grigoriy Matusewitch, Raphael Sonnenberg and Piroshnikoff.