This is a new film coming out this month about life in the Jehovah's Witnesses cult and what happens when a member strays and questions the faith. There are many parallels to Armstrongism. The JW's also believed the end times were happening in 1975, they practice public disfellowshipment like the COG does, they practice shunning like the COG does, and much more.
It is an interesting side note that Herbert Armstrong had many JW booklets in his basement walk-in safe that were marked and highlighted. The claim that HWA amalgamated his beliefs from the SDA's, JW's and Mormons, carry way more weight than many want to believe.