Brewer, John, Cambridge, by wife Ann, his first, had John, b. 10 Oct. 1642; and Hannah, 18 Jan. 1645; removed probably to Sudbury, perhaps after m. 23 Oct. 1647, Mary, dau of the first John Whitmore, prob. and had Mary, b. 23 Sept. 1648; William, 6 Oct. 1653; and Sarah, 27 Mar. 1658. (James Savage First Settlers to New England vol 1, page 243-244)
John was born in 1619. John Brewer ... He passed away in 1669. 
WikiTree profile Brewer-852 created through the import of 25a.GED on Jan 8, 2012 by Michael Lechner. See the Changes page for the details of edits by Michael and others.
Source: S221 Author: The Church of Jesus Christ of Latter-day Saints Title: International Genealogical Index (R) Abbreviation: Family Search IGI Publication: www.familysearch.org Copyright (c) 1980, 2002 Italicized: Y Paranthetical: Y Data: Text: Birth: About 1621 Of, , , England CONT Death: 23 JUN 1684 CONT Burial: 01 JAN 1690 Sudbury, Middlesex, Massachusetts CONT Father: Thomas Brewer CONT Spouse: Mrs. Ann Brewer Note: Film Number: 471020 CONT Film Number: 170659 CONT Page Number: 389 CONT Reference number: 8603 CONT Film Number: 457880
Brewer-4977 and Brewer-468 appear to represent the same person because: Same/similar vitals; same death date. At least one of his spouses is also a duplicate; other one probably is, but need to confirm her LNAB.