Here is a video that Van Robison recommends to readers here. It is about the Jehovah's Witnesses and how aberrant their beliefs are. Watching it though you will see direct parallels with Armstrongism. We held many of these same beliefs. Particularly because the JW's was one of three cults that Armstrong copied doctrines from (JW's, Mormons, and Adventists)
The film is made in the mid 1980's.