The Rivera mural is at City College of San Francisco. http://www.riveramural.com/home.asp?language=english
Bolerium Books, tens of thousands of used leftist books 2141 Mission St, 3rd floor in S.F. Ring the buzzer at the front entrance. http://www.bolerium.com/ A used book store on the corner past Modern Times, http://www.mtbs.com/ the new lefty book store, has a copy of a pamphlet by a 80+ old USA maoist who calls the October League, revisionist. Mgr. of Modern Times told me on Tuesday that book sales are down to what they were a decade ago, so buy up.
Stop into the CISPES office off of 26th St. too as well as City Lights. And go to Pacifica to visit David Walters, notorious Trotskyist w/ a Ducati.