After the Judge died, the Society under Knorr and Franz began making changes, refining some of Rutherford's doctrines. As a result a split happen. The groip is mainly in Romania, with about 30,000 followers at the time. They were discovered after the fall of communism. The Society sent their representatives and found 3 sets of Jehovah's Witnesses. Bible Students who took the name Jehovah's Witnesses, but only studied Russell's writings, the Rutherfordites, and the JW's. The Society tried to convince them of the new light, but many of them didn't buy into.
Some of the differences seem minor to me, one that I know of is they stick to Rutherford's interpretation that the Supreme authories are Jehovah and Jesus. They do have groups of supporters throughout Europe, Africa and Canada. Their International conventions have delegates from all 4 corners.
There is a former member of this groip on the net by the name of Rus Virgil.
RR