Over at Only Maybe, Bogus Magus points to an article in the Public Domain Review by Mike Jay on John Robison's classic book about the Illuminati conspiracy, Proofs of a Conspiracy against all the Religions and Governments of Europe. The book is cited in Illuminatus!, of course, and the posting has useful Illuminatus! study links.
Here's my take from 2014 on the same article.
Check out Mike Jay's official site. He's written books that I want to read, and that many of y'all would likely find interesting.