My understanding is that today, most men's clothing buttons left-on-right, i.e. the buttons are on your right. A Hassidic kapote or bekkeshe reverses this, but if you order a "Litvish" ("Lithuanian", i.e. non-Hassidic) version, it comes left-on-right, the same as an ordinary men's suit or shirt sold today.
I was looking at a photograph from right about 1900 of a Jewish Lithuanian family, and the father's frock coat is clearly right-on-left.
Was that common in the non-Hassidic world at that point?