Some more information courtesy of a Ukrainian colleague of mine:
Б. М. It stands for Божией Милостию, which means “By the Grace of God”. Therest means “Nicholas II the Imperator and Autocrat of all Russia”. The abbreviation Г. after 1896 stands forГод which simply means“year”. Though I could read the name Nicholai II, I was curious as to what the remainder said.