I am related to Northampton Co Penn Mayers. I have a Mary "Polly" Fry (nee Mayer) born 1803 born in Northampton to father, Henry Mayer, presumably also from Northampton Co, Penn. My records show that Henry's family also probably spelled the name Myer. He would have been born around 1775 or a bit later. He may be a son of the John Mayer you are referring to. Have you found any more information since your last posting?