I realize this post is coming many years after your post, but I wanted to see if one of my distant relatives could possibly be related. I have yet to begin my research on the Deschamps family, but I do have Augustin Hunault Deschamps in my line. I do not have a date or location of his birth, but he married Marie-Francoise Lalonde and they had Elisabeth Hunault Deschamps in 1771. Does this fit into your line?
Erin (Garrow-Gareau) Cogar