How old were the actors in Γαμπρός Από Το Λονδίνο (1967)?

Betty has become engaged, for her father’s sake, with a hard working and kind young man, Kostas, who works at a store selling electrical appliances that belongs to Betty’s father, Mr. Periklis. The latter values Kostas and truly wants to make him his son-in-law. Kostas saves the life of a sensitive girl, Mary, who tries to commit suicide because her English lover deserted her. Later on, he is persuaded to impersonate a rich Englishman in order to help Mary deal with her father, Mr. Kyriakos, who is trying to force her to marry someone against her will.