1) Thanks to Wally Conger, I've stumbled onto the motherlode! KoPubCo (publishing division of Triplanetary Corporation) has a huge treasure-trove of publications by the Movement of the Libertarian Left. All for sale, of course!
Among other things, it has a complete run of Vol. IV of New Libertarian and New Libertarian Notes.
Along with the New Libertarian Manifesto, it has both issues of Strategy of the New Libertarian Alliance (collected critiques of the Manifesto, including commentary by Rothbard, Irwin Strauss, Bob LeFevre, George H. Smith and Kerry Thornley).
Even better, according to the cover, the April/June 1981 issue of New Libertarian includes Chapter 2 of SEK3's Counter-Economics. Since I can't see any chapters similarly featured on any of the other issue covers and they don't provide tables of contents, I've contacted KoPubCo for information on what issues Counter-Economics was serialized in.
You can bet I'll be ordering a shitload of stuff from these guys.
2) Brad Spangler has an excellent site up called Agorism.Info. Among other things, it's got pdf versions of the New Libertarian Manifesto and Agorist Class Theory, along with several easy to print pamphlets promoting agorist ideas.