I spent much of last night reading a book by David Pack, of the Restored Church of God. In the book, Pack, succssor to Herbert W. Armstrong, of the Worldwide Church of God, writes that Armstrong was the "church of Philadelphia" and that everything he, Armstrong, went through was foretold by John. Its theology is just as steeped as the WTBTS, and its members are just as determined that they are the fulfillments of God's choice people. To them, however, the issue isn't the divine name, but the Sabbath. Peck and Armstrong quote the scriptures stating that the sabbaths of God are a sign between Him and His People, and that anciently they refused to abide in those sabbaths. So everything they see in the book of Revelation is tied in to Seventh Day worship. In other words, they see themselves in every fulfillment, going so far as to say that Herbert W. Armstrong was the Elijah who was to return as stated by the prophet Malachi, and that the youth outreaches he performed was what turned the hearts of the children to that of their fathers.
In the same sense, the Jehovah's Witnesses and the GB see themselves as fulfillments of scripture, and in both cases, of course, neither has had it confirmed of God through angels or visions, and so forth. And though Pack argues that the name of the true church has always been the "Church of God" (confirmed by twelve references in the New Testament), the JWs always have the scripture, "Ye are my witnesses, saith Yahweh."
Pack's church, if one compares the two claims, stands on much firmer ground, but both are grounded in assumption.