Welcome Danny!I am not that guy but I would dearly love to play in a game of FoDG, I am hoping to run a PbP game here but don't feel 100% with the system yet. I do get Gumshoe systems and have played and run in Trail of Cthulhu games.
For the record, I'm terrible with the rules, but it hasn't been an issue at all
(I either clarify in advance via the OOC thread, or I get yelled at via OOC comment in the IC thread... )
I thoroughly recommend investing in a copy of FoDG on its own merits, but it's probably not critical to own it to play this PBP, especially if you are familiar with GUMSHOE.
Paul is very solid on the rules and there are knowledgeable people elsewhere on RPGnet on the odd occasion when even he has a question.
Character creation is the biggest initial thing that owning FoDG would be good for, but creation can be done for free via the Black Book website.
(N.B. The Black Book generated a couple of errors when I used it, but it gets you 95% of the way there, and we can help you connect as necessary from there).
Paul, my PM outreach was politely declined, so we are ready on that front.