I think that you should add to your theory, why they would go back in time? Did it just happen *snap* like that? Or did something cause it? Was it a space time continuim?
Rousseau has been on the Island 16 years, so that would mean she go there in the early 60's? You have some solid points, but I beg to differ on the Island being that far back in time.
I believe that the records were written in to show that Dharma was not a new project and that not much has happened in the hatch for many years. Plus the writers seem to like those styles of music.
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