The Loiselle Marriage Index is in the National Archives of Canada in Ottawa and in many Genealogical societies and Historical Societies in Quebec. If you give me the place of birth or of mariage of your Loiselle ancestor I may be able to help in the longer term. I have done my genealogy having this basic information and with no mayor constraints. Plus I have a roster of Loiselle marriages in the Richelieu region; there is however, a different branch of Loiselles from the pioneer also Louis Loiselle who settled in the late 1600's near Quebec City. That pioneer gave birth to a different branch from those of the Montreal pionneer.