hi, Not much luck, but here is what I found so far:
In the Montebello Baptisim book: Michel Hubert Blais , born 21 dec 1856 baptized o 11 jan 1857, father Joseph Blais(farmer from Lochaber), mother, Louise Duval godfather Hubert Blaie(another variation of the name) godmother Desanges Pelletier
In Eloi Talbot, Genealogie des comtés de Montmagny...: Antoine Hubert Blais married to Soulange Pelletier in St-Pierre-de-la-Rivière-Sud on 29 jan 1828. Antoine's married siblings:
Brothers:Télesphore, Jean-Baptiste, Louis-George Sisters:Françoise, Desanges, Elisa, Thérèse, Z. Nathalie.
Maybe there was another brother(Hubert) for which there was no listed marriage.
As for Louise Duval, sorry nothing there. And I tried to find marriage for the Lochaber Mission: but without any result. By the way Lochaber is now in the area ofThurso and St-Sixte.