The Sancomb name was derived from Gagné dit St-Come. See: https://www.ancestry.ca/boards/surnames.gagne/484.212
I doubt that this Census entry is theirs if I look at the childrens' names: "United States Census, 1870," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M8KV-3T7 : 12 April 2016), Henry Petrie, New York, United States; citing p. 29, family 204, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 552,597.
1880 US census in Chateaugay, Franklin, NY: https://www.familysearch.org/ark:/61903/3:1:33S7-9YBV-BPF?i=18&cc=1417683&personaUrl=%2Fark%3A%2F61903%2F1%3A1%3AMZ8Q-FCN
1910 US census in Ellenburg, Clinton, NY: https://www.familysearch.org/ark:/61903/3:1:33S7-9RVC-1LJ?i=8&cc=1727033&personaUrl=%2Fark%3A%2F61903%2F1%3A1%3AM5Q7-XLM
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