I have a copy of "Early Families and Marriages" in Bristol and Bremen, Maine. It is a compilation of various notes obtained from the manuscripts of Prof. John Johnston, L.L. D. author of "History of the towns of Bristol and Bremen in the State of Maine".

Although I am confident it is not complete reflection of all the families in Bristol because it does not contain all the families listed in U.S. Census Records, it did list the following information about two Upham families. (One is your Jabez and Hannah)

"Children of Jabez and Hannah (Burgess) Upham of Athol, MA and Bristol, ME:
Ephraim b. Feb. 25, 1770
Lydia b. Oct 25, 1771
Judith b. June 4, 1773
Jabez b. September 30, 1775
Josiah b. May 15, 1777
Isaac b. June 3, 1779
John b. April 22, 1781
Hannah b. June 23, 1783
Deborah b. April 17, 1785
Abigail b. August 19, 1787
Simeon b. August 30, 1791

Children of John and Sally (Weston) Upham:
Hannah b. Aug 5, 1805
John b. October 27, 1806
Eliza W. b. March 22, 1808
Hiram b. January 5, 1810
Sally b. Dec 18, 1811
Salena b. Feb 1, 1814
Simeon b. Mar 24, 1816

There is also a note on page 14 re: Betsey Upham's marriage to Miles Thompson in Bristol in 1816. Marriage officiated by Rev. Enos Baxter. Note as follows:
"She was the daughter of William and Elizabeth (Fosset) Greenlaw and widow of Ephraim Upham son of Jabez and Hannah (Burgess) Upham of Athol, Mass and Bristol, Maine. Ephraim Upham died at Bristol Feb. 26, 1796, aged 36 years. Her marriage with Upham is not recorded on Bristol records; the intention was published Aug. 19, 1789"