Well the most easy way to get the legal documents(Contracts) is to be lucky like me: My father gave them to me, he had 75 contracts.I dont know where he got them neither does he remembers(he's 90 years young). I have been able to get the one missing and copies of the ones not legible in the following manner: 1- I went to: Les archives Nationales du Québec in MTl on Viger street. 2- Ask for; "Les Inventaire des greffes des notaires sous le Régime Francais" This collection is many volumes thick 7 or 8 . 3- You must know which notary to look for. In the case of Claude Robillard, the main one is Antoine Adhémar, he practised from 1668 to 1714 in Champlain and Ville-MArie) and his son Jean-Baptiste continued from 1714 to 1754,there are also the notarys named Mauge and Bégnine Basset(I have yet to get copies from these last two). 4- once you know or have the list(which i can send you and save you all these problems), you have to make copies of all the documents, this could be expensive as they cost $0.15 per sheet(with all the contracts, it can run you into 400 or 500 sheets. 5- Once you have the contracts, you must "translate" them in todays French, which is the most daunting task; in the five years since I started this , i have translated about 35 since i have no formal training in paléontography(i think this how it is spelled). 6- I got copies of a book(at the local genealogical society) that give examples of Anthoine Adhémar handwriting with examples of different way of writingin that time périod.It is not an easy task i must advise you, but i take my time and maybe do 1 or 2 per month; also i have not done any for the last year since i moved to Trois-Rivieres and must rebuild our old house to aspect it must have been when it was build in the 1940's. 7- Since you live in Ottawa, you must be able to obtain the same documents in the National Archives probably.
Any way, I wish you lot's of luck if you decide to undertake this task.I find it very interresting because it relate the way of life of that period(Thank God I'm living today)