I am aware that it depends on the individual guitar to some extent. No one I knew bought new in the sixties,a question that it was the myth at least that old was better sound. We mostly had Martins so I heard a few. Funny that even in the sixties,people liked the Guild for a 12 string. I never knew anyone in the sixties that had a guitar set up;perhaps no one told me. Not aware anyone did anything but play them as found;except Big Joe Williams who added 3 strings.