The Bradbury Building is located at 304 South Broadway in downtown Los Angeles. The building is famous for having featured in numerous films, books and television series.
For the 1982 film Blade Runner, it housed J.F. Sebastian's apartment, and its roof was the scene for the famous rooftop chase sequence at the end. The building also featured in Double Indemnity (1944), D.O.A. (1950), M (1951), I, The Jury (1953), The Indestructible Man (1956), Good Neighbor Sam (1964), Chinatown (1974), Avenging Angel (1985), Murphy's Law (1986), Wolf (1994), Disclosure (1994), Lethal Weapon 4 (1998) and (500) Days of Summer (2009).
Here, Pynchon is referring to the 1969 film Marlowe, based on Raymond Chandler's novel The Little Sister, in which the famous private-eye is played by James Garner.
This is Jimmy Olsen, a young photojournalist who works at the Daily Planet alongside Clark Kent and Lois Lane. He idolises his coworkers and has a strong friendship with Superman. He posesses a wristwatch that can signal Superman from anywhere in the world. He is often in need of rescue by Superman.
The 'V' peace sign was prominent in the American national consciousness at the time of the publication of Gravity's Rainbow. President Nixon had made the gesture his trademark when he ran for President in 1968. At the time of the novel's publication, Nixon was facing increasing pressure over investigations into his role in the Watergate scandal. Pynchon's inversion of Nixon's trademark gesture is a tacit condemnation of the President, following on from his quotation of Nixon in the epigraph to Section Four of the novel.
Nixon would end up resigning from office the following year, 1974. His last act as President before boarding the Marine One helicopter to return home was to turn to the crowd and give his 'V' salute one last time.