You prob. already have these but all I could find besides what you posted:
Digby was established in 1837; before that date, it was part of Annapolis.
ON the 1827 census for Annapoplis, there are two Dunns: John & Ezra.
ON the 1838 census, you can search for Digby and find a Wm Dunn - a yeoman / 10 in household & Charles, a shoemaker.... just tally marks for the rest of the family. (In Annapolis, find John, Ezra, & Charles.)
Your Wm is listed later as a shoemaker too.
By the ages of the children you have listed, seems like Henrietta may have been a second wife?