It's eerie- last time I searched, there were at least two references to where you could buy "Cover-Up!" and several more of David's work in general. Memory Hole, anyone?
Fwiw, I've seen the Memory Hole at work in Arkansas. When the "tainted blood" scandal got particular malodorous in the Bubba days, an outside agency -- from California -- was called in to investigate. Its report was damning. Every copy disappeared, even from state libraries and official files. Then the investigating agency suffered a "mysterious" fire, yes, in California, and its own files were destroyed. A summary report of the findings also disappeared (much shorter, less detailed, but still damning). One legislator remembered that he'd put his copy away in his garage. Mike Galster (author of BLOOD TRAIL), his helper and I drove to a small town, retrieved the document, and went straight to a copying facility. That whole adventure was plenty scary.