the author of Rebecca, Daphne DuMaurier has written several thrillers, like My Cousin Rachel and Jamaica Inn (both also made into movies in the B&W era). You might also like Mary Stewarts thrillers, books, set in the 50s & 60s, such as Touch not the Cat, The Ivy Tree, Nine Coaches Waiting, This rough Magic etc.
Helen McInnes, 40s & 50s with a cold-war flavor, she had one about an American girl caught in Poland when the Nazis invaded which is an excellent book about that time.