I have the 1841 Census booklets for most of the surrounding area including the Parish of Hoddam, within which Ecclefechan lies. The only adult William KENNEDY listed in Ecclefechan (Village) is age 40, Occupation Joiner.
Have also checked the 1941 booklets for the Parishes of :- Half Morton, Middlebie, Dornock, Gretna, Cummertrees, Kirkpatrick Fleming, Annan Landwards and Annan Outskirts, The only other adult appears in Annan Outskirts - Crecca Village - William KENNEDY, Age 35, Ag Labourer. No School Masters evident.
Hope this helps.....Sweetfannyadams.