Hello Jerre,
I am also searching for my Coburn roots in Vermont. Last summer I took a trip to Northfield Falls, Vermont where my 3rd great grandparents lived and were layed to rest. I don't know if this will be of any help to you or not but am willing to share what I have on my Coburn line in hopes that yours may connect.
My Coburn line were of Irish ancestery. The first one I have been able to fine is Thomas Coburn and his wife Rebecca Warren. They moved to Vermont from Maine. I do not know if Thomas had any brothers or sisters but believe they had only one son, Washington Coburn who was born 8 Aug 1815/16 in Northfield, Vermont soon after Thomas and Rebecca arrived in Vermont. Washington married Harriet N. Thompson and they had the following children that I know of: George F.Coburn b. about 1840, Benjamin Franklin born 8 Oct 1841 m. Lucinda Sulham the daughter of William Sulham and Mercy Woodard/Woodward; Asa T. Coburn; Curtis H. Coburn; Hannah R,. Coburn and Charles H. Coburn.

I do not know where Thomas Coburn and his wife Rebecca are buried but Washington Coburn and his wife Harriet are buried at the Northfield Falls Cemetery in Northfield Falls Vermont.

Benjamin Franklin Coburn married Lucinda Sulham and they had the following childran:
William Coburn b. 31 Aug 1866, Gertrude Mae Coburn b. 22 June 1869; Harriet Coburn b. 19 May 1872; Frank Coburn b. 13 Mar 1865; Leon E. Coburn b. 1 Sept 1877; Zoa I. Coburn b. 21 Mar 1882 and George Frank Coburn b. 28 Jan 1874.

I found a William Coburn in the same cemetery that I can not connect with my Coburn line yet but, believe he is connected because he lived in the same town.
William Coburn b. about 1801 died 5 Jan 1864 age 63 years. His wife Eleanor Libbey b. about 1803 died 20 Nov 1855 age 52 years. Their children where:
Alonzo L. Coburn; Mary E. Coburn; Laura Coburn; Sally Coburn; William Coburn b. 7 Jan 1837 d. 5 Apr 1899; Herman Coburn; John Coburn; and James M. Coburn.

Hope this will be of some help to you. If you would like further information that I have on this family, write me at any time.
Good Luck,
Angie