But then the premise of the post doesn’t make sense. People in the 50’s and 70’s didn’t have different accents. They used different vocabulary, but accents have not changed much in the past 70 years. Quick accent changes just don’t happen that quickly outside of extremely isolated groups. You might be thinking of the transatlantic accent from tv and radio or whatever, but that was an affectation by actors and presenters. It wasn’t real.