Rex Thompson was a popular child actor in the Hollywood of the 1950’s.   He was born in 1942 in New York City.   Among his more popular films were “Young Bess”, “The Eddy Duchin Story” and “The King and I” as the son of Deborah Kerr.   His last acting role was in an episode of TV’s “The Fugitive” in 1966.   His IMDB website here.