I ran two classified ads in Rolling Stone for my Firesign Theatre newsletter. They were in issue #105 (Cooper, 30 March 1972) and #150 (Hefner, 20 December 1973). The zip file contains PDFs of the newsletters, plus my introductory letter to Firesign at Columbia Records. I met them a few months later at the Martian Space Party film premiere in 1972.
Chromium Switch logo, “Filthy Pirate Pub” cartoon (CS #3), and “Jesus Retardo” cartoon (CS #5) by J. Scott Stewart