I think there was a sort of meta-fictional "interview" recording of him on Grey Lodge's website, somewhere.
Anytime Joesph Matheny's name is mentioned, you can be assured that the fiction extends well beyond where you would expect.
Does this Matheny fellow have something to do with PwoC other than being among the references?
He edited and published it, and also did the interview with Mack, IIRC.
Also, the mention of Ong's Hat, later on in the book, is a direct reference to an extremely intricate and mindfucky ARG Matheny ran back in 2000, before most people even knew of ARG's. He does that alot, setting up mysterious websites and creating games, only to spill the beans 7 or 8 years later.
The guy's like the ultimate Discordian prankster, and I know the Grey Lodge crew tend to help each other out on projects, even if
most of the work comes down to one person or so.