In Wait (1848: 50, see sources below), we see that William GUTTERSON is a Freeman of Ipswich in December of 1648.  The minimum age for being a Freeman was 20, so William could not have been born later than 1628.  That the Freeman of 1648 is the son, not the father, is deduced from the fact that the father is presumably the one who died in 1643.  I have yet to find proof that the father of William GUTTERSON ( -1666) is William GUTTERSON ( -1643), but there appear to be no other male GUTTERSONs in Ipswich at the time, except these two, so there is a strong probability they are father and son.

1.  Clarence Almon Torrey.  1985.  New England Marriages Prior to 1700.  Genealogical Publ. Co., Baltimore, MD.  On p. 331:

GUTTERSON, William ( -1666) & Elizabeth __?__, ?m/2 John CALLUM/COLLINS?/KILHAMS? 1670; b 1658; Ipswich.

2.  Luther Wait.  1848.  "Ipswich Proceedings." New England Historical Genealogical Record. 2(1): 50-52.  From the Record Books of the town of Ipswich, Essex Co., MA.  The author considers that the list of 161 names signed to the document below probably constituted all the Freemen of Ipswich at that time.  On p. 50:

At the generall Towne Meeting held the 19 of December, 1648. Wheras the Inhabitants of this Towne have engaged themselves to pay yearly on the 10th day of Decembar unto Maior Denison, soe long as he shall be theur Leader, the sum of Twenty four Pounds, Seven Shillings, in way of gratuitye, as under there hands may appear; and because it is most manifest the sayd sum will not be raysed unlesse some better order be taken for the same, Espeshally in respect of the Alteration and change of the Inhabytants.  It is therefour ordered that henceforth the seaven men shall, yearly in November, put the sd summ of 24£ 7s into a rate, proportioning it upon the Inhabitants.  Having alsoe respect to the bill of Subscriptions of the Towne from Year to Year to be Levyed and colected by the Constable, and payed unto the Sayd Maior Denison, on the 10 of Decembar, yearly, soe long as he shall continue to be leader of this Company. Voted by the Town at the generall Towne meeting above mentioned.  A list of names of those that did subscribe theur severall somes yearley, while he continued to be our Leader... Wm. Gutterson, £0 2 0...

3.  John Farmer.  1829.  A Genealogical Register of the First Settlers of New-England...  Carter, Andrews, & Co., Lancaster, MA.; republ. 1964/76/83. Genealogical Publ. Co., Baltimore, MD; republ. 1998. Broderbund CD-354.  On p. 131:

William Gutterson, Ipswich, MA, 1648.

Apparently refers to the above (Wait 1848: 50).

4.  The Preston/Lindsey Trail, self-published (1995) by Rosaline Preston (17369 Road 6 SE, Warden, WA 98857) and Carol Huber  (10508-A Witter Springs Rd., Witter Springs, CA 95493).   On p. 5:

Not much is known of Willaim Gutterson but he held a share of Plum Island in 1644 and was probably a fisherman.  It is thought he was from the Island of Jersey.

5.  LDS.  Family Search: Internet Genealogy Service:  AF - Ancestral File (online at FamilySearch.org).  Gives William's birth as 1643 in Ipswich.

6.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).  Gives birth date/place of William Gutterson as ca. 1628, Isle of Jersey, England, which I find much more plausible than 1643 in Ipswich.

7a.  Frederick Adams Virkus, ed.  1933.  The Compendium of American Genealogy.  Vol. V.  Institute of American Genealogy, Chicago (1968, Genealogical Publ. Co., Baltimore, MD;   1997, Broderbund CD-200).  On p. 352:

7b.  Frederick Adams Virkus, ed.  1937.  The Compendium of American Genealogy.  Vol. VI.  Institute of American Genealogy, Chicago.  (1968, Genealogical Publ. Co., Baltimore, MD; 1998, Broderbund CD-200).  On p. 455:

8.  Broderbund.  World Family Tree.  Vol. 11, Pedigree #1468.