Whenever I think of the Byrds, I think of David Crosby, and Crosby, Stills, Nash and Young. My favorite song of their's is Wooden Ships. Go to youtube and type in Wooden Ships CSNY Lyrics. Listen and follow the lyrics.
I look at it as an anti-war song about future nuclear destruction. There is mention of wondering if the "purple berries" are safe to eat, an opposing soldier asking which side won, and about "silver people on the shoreline." I think this refers to men in silver hazardous suits . You and Gramps listen and see what you think.