Hi Defender,
Concerning the 1931 name change to "Jehovah's Witnesses":
1931 [New name of "Jehovah's Witnesses" adopted, to "distinguish" themselves from "dissenters" and "Christians"] {WT 1931 278-9} [How then could any reference to "Christ" have been dropped when the declaration had been made that "We always refuse to be called by any other name than that of our Head [Christ]. Christians continually claiming that there can be no division among those continually led by his Spirit and example as made known through his Word." {WR Mar 1883 458} ?]
By gradually replacing locally elected elders with his own appointees, he (Rutherford) managed to transform a loose collection of semi-autonomous democratically-run congregations into a tight-knit organizational machine run from his office. Some local congregations broke away, forming such Russellite splinter groups as the Chicago Bible Students, the Dawn Bible Students, and the Laymen's Home Missionary Movement, all of which continue to this day. But most Bible Students remained under his control, and Rutherford renamed them "Jehovah's Witnesses" in 1931, to distinguish them from these other groups.