My audacious suggestion to the Ballad-L list that the song was composed during the 1960s "revival" was made on the basis of circumstantial inferences only. Now that I read stanza 1 and the chorus, posted by Jon Boden, I'm even more persuaded that somebody was, er, fakin' em.
That density of specific detail isn't a feature of older ballads. The phrase "I never *really* fell in love" expresses a kind of inward analysis of one's own deeper emotions that became commonplace in song only after the dawn of the pop psychology era in the late 1920s. That and "Her eyes were saying, 'Come and take a chance on me,'" (with its coy echo of the 1943 Benny Goodman smash, "Taking a Chance on Love") seem like very modern expressions to me.
Also, I don't believe that eyes generally "say" anything in traditional or broadside songs. They may shine (like diamonds), but they don't speak.