'... John, the heir of Edward, was shown in letters patent issued 3 Dec 1633, to his grandfather John Blinco of Marston St. Lawrence, Northants to have been born 5 Jan 1619. Other records at Marston show that he, age 21 ... had died at that location before 1640. ...
120 ... John GRESWOLD, born 5 Jan 1619 in Cubbington, Warwickshire, England. John recorded by inscription at Merston [sic], St. Lawrence, Northants as having died by 1640... No issue.'
While page 33 indicates that he died 'before 1640', it also indicates that he was 21. A likely interpretation is that he had died by the time of the 1640 inscription, which may have been shortly after his death.