according to my files, this information was given to me by Christine McKinney in May 2007. I don't have the original source.
I agree with you for the birth dates of Jean-Marie Ducharme and Marie Roy. I believe they were married in or around Sault-Ste-Marie circa 1826. I did not made any research there myself, but a friend did: it seems that no registers exist for that period.
BTW, in your message no 1223, you wrote about «Missouri Riverbottoms». What does «Riverbottoms» mean? I dit not found the word in my dictionary.