I have one too. And indeed pushing and pulling is the other way around as we know it. But this is the ncase with nearly all Russian instruments of the "push-pull family". The scale starts pulling on the second button. The instrument has three basses: the two buttons on the outside produce the bass and the chord. If you push these buttons hard enough, the hammers attached to them will hit the bells which then will ring in time. The third button on the lefthand side also produces the chord, but one octave higher. These chords have quite a harsh sound. The airvalve is not at the back of the basses, but on the side of the box itself, so you have to move your thumb inwards to use it.
The instruments are three-voiced: two sets of reeds are put directly and flat on the soundboard, the third (the lower octave) is on a conventional reedbloc (only just with reeds on one side).
The most common tuning (believe it or not :)) is Aflat.
Robert