Tracing John Aitken born 1729, Greenhill, Auchenhay, Kirkcudbrightshire, Scotland. He immigrated to Prince Edward Island in 1775.
There is a John Aitkin baptised in 1729 in Colvend who might be worth a closer look. His baptism record is on https://scotlandspeople.gov.uk. You can search for free and you can view the record image if you purchase credits. Parents: James Aitkin and Janet McLeduff.