I knew about Radio Free Bolinas (my mom's cousin , whom we'd visit from time to time, lived in Marin County), and thought that helmet decal was a known thing -- but now that I think about it, I don't know from where I thought it was a known thing. I'm delighted to see attention brought to it. And I definitely didn't know about that Redbubble store and need to check it out. Thanks, robn1.