Further to my last post...
Found this great website: http://genealogiequebec.info/frames.html
Looks as if there is no record of where Francois Decelles and Marie Anne Julliet come from. According to this site, they were married around 1711 and had a kid Francois Decelles and you can start tracing our family from there.

NB There is another entry for a man Francois De Selle 1652-1714 who trained horses and died of a head injury. He was married to Marie Catherine D'Auteuil in 12/12/1713. They had a son Jean Francois Marie 5 Oct 1714. Marie Cath remarried after her husband's death in 1718 and moved back to Rochefort, France as she died there in 7 Dec 1745. No other info on this son or who he married, his kids, or if he also went back to rochefort.

Did Marie Anne Juillet die shortly after marriage, and Francois remarry to Marie Cath D'Auteuil? Odd that the surname changed spelling. The first marriage has not much information, but the second is quite detailed and seems a bit more upper class. I'm not sure it is the same Francois DeCelles!

As ever, any information on DeCelles-Juillet marriage and where they came from would be most appreciated. Ditto for the son of DeSelles-D'Auteil