I had an email response from Varick Chittenden of TAUNY to my enquiry about the Willard manuscript. Here it is:

"Thanks for your inquiry. FYI, the handwritten copy we have in our archival materials is from a file compiled by Miss Edith Cutting beginning nearly 70 years ago. Now in her late 80s, Miss Cutting, who collected largely from family and neighbors in her native northeastern Adirondacks and the Champlain Valley, was a student of the legendary Dr. Harold Thompson and did meritorious fieldwork in those days. She donated some of her large collection to TAUNY, from which this one piece comes.

The limited info on the House Carpenter is: from Cutting's "Songs from Aunt Lois" file, and it is signed Sarah A Willard, Moriah Center NY, April 28, 1869."

They say the date is "1869". That should be authoritative, but it sure looks like "49". I've come across Miss Cutting's name before and we can look further there. I wonder who "Aunt Lois" was. And let me take this opportunity to credit "The Edith Cutting Collection in the TAUNY Archives" for our use of this material. And a big thanks to Varick Chittenden for getting back to me!