Knox seminary hosts the John-Revelation project. I'm not familiar with these two authors, but one of them, Warren Gage has apparently written his PhD on Revelation. R. F. White, in a review of Kistemaker's commentary on Revelation notes that:
To date, the most thorough application of literary intertextuality and typological hermeneutic to the interpretation of Revelation is Warren A. Gage's groundbreaking study, St. John's Vision of the Heavenly City (Ph.D. diss., University of Dallas, 2001). Gage identifies a pervasive lexical concordance between Revelation and, of all things, the Gospel of John, which in turn exposes an astounding array of consecutive and chiastic correspondences between the books. Not only does this concordance establish common authorship; it also compels the necessity of a lectionary reading of the two books as companion volumes (much like Luke and Acts), the one hermeneutical to the other.In reading through Revelation, one is struck by the similarity of words and concepts it presents. How far does this go to suggesting a common authorship between the writer of the gospel of John and the Apocalypse? This is a fascinating exercise in historical enquiry. And I've not even got into it in any great depth! Anyway, the John-Revelation project looks interesting for those keen on delving into these issues... One should also frequent Alan Bandy's Cafe Apocalypse for regular comments on such issues.