If I can beleive the stuff I'm going through on Wikipedia, the anime and the manga of Metropolis aren't that much alike - the anime is based mroe heavily on the silent movie. Apparnetly Tezuka hand't seen teh movie and was instead inspired by the poster. (That's not referenced, though, so take it with a grain of salt. I'm unsure because Tezuka was a movie freak and saw as many as he could growing up.)