=== Evidence-Based Content from The Great Migration Series ===
— The origins of Isaac Willey are unknown.
— Isaac Willey was not a son of Allen & Alice (Mason) Willey.
Robert Charles Anderson (Fellow of the American Society of Genealogists), The Great Migration Directory: Immigrants to New England, 1620–1640 (Boston: New England Historical and Genealogical Society, 2015), 374:
Willey, Allen: Saleby, Lincolnshire; 1634; Boston…
Willey, Isaac: Unknown [origins]; 1640; Boston, Charlestown, New London…
With respect to “Alan Willey,” below are verbatim excerpts from Robert Charles Anderson, The Great Migration, Immigrants to New England, 1634–35 (2011), pages 427-428:
ALLEN WILLEY
ORIGIN: Saleby, Lincolnshire.
…
FIRST RESIDENCE: Boston.
…
BIRTH: By about 1603…
MARRIAGE: Saleby, Lincolnshire, 15 May 1628 Alice MASON…
…
ASSOCIATIONS: No connection has been found with Isaac Willey who appeared in Boston by 1640.
<== end of verbatim excerpts from The Great Migration