The age on this student at Cambridge is very close to your John Melson.....if he entered the college at age 15 in 1665 it would put his birth date at 1650...also, it says his father is deceased and he was ordained by 1670...maybe he was more of a missionary to the new world than a part of the headright program....
Cambridge University Alumni
Name: John Melson
College: SIDNEY
Entered: 1665
More Information: Adm. sizar (age 15) at SIDNEY, June 1, 1665. Father deceased. B. in Lincolnshire. Matric. 1665; B.A. 1668-9; M.A. 1672. Ord. deacon (Peterb.) Sept. 19, 1669; priest, May 29, 1670.
Possible immigration record?
Name: John Melson
Year: 1672
Place: Maryland
Virginia Quit Rent Rolls, 1704: Accomac County
John Melson 180 Acres