I always get a kick from Sir Cedric Hardwicke as the master sculptor, what a ham! Love the way he hogs the camera in all his scenes. He also played Pharaoh Seti I, father of Rameses II, in Cecil B. DeMille's 1956 epic, "The Ten Commandments" that airs every Easter on TV. And he was also the narrator in George Pal's 1953 production of H.G.Wells' "War of the Worlds", it's his voice you hear in the opening scenes of the solar system tour.
Btw, that stern looking guy as the city council chairman was the wonderful actor Raymond Massey. He went on the greatness playing both abolitionist John Brown and Abraham Lincoln in films.
Be sure to check out the scene with the space gun. Some excellent scale model work.