Let me clarify, I have not found a statement to that extent in any of Russell's publications. I understand that the finished mystery is not accepted by the Bible Students, that is why it is not found at the website, www.ctrussell.us.
As I stated the foreword says that Fisher and Woodworth compiled the FM using previous statements by Russell in his publications. To date I have not found the one re Revelation 5:8 attributing it to meaning Jesus is God or that substance.