Gerard Halle Montreal

I am looking for information on my grandfather, Gerard Halle. He was born on May 22, 1920 to Alphonse Halle and Adiana Duquet. He died on January 5, 1991 at Saint-Foy in Charlesbourg. Gerard married Monique Pelletier (my grandmother), daughter of Hilaire Pelletier and Josephine Pelletier on October 23, 1941 at Notre Dame de Tres St. Sacrement in Montreal. My father, Lionel Joseph Halle was born to them on December 1, 1941 (not sure on the accuracy of this birthdate based on the marriage date.) Gerard then served in the war and upon his return, could not find Monique, so he remarried a woman by the name of Jeannine Dutil on May 14, 1955 at Saint Roch, Quebec City. Monique died on October 27, 1953 of lung cancer and her death certificate shows she still held the Halle name although it was believed she married a man with the surname, Meunier. Gerard served as the fire chief to a fire station just outside of Valcartier (it is believed during the 70s). My father was born Joseph Lionel Gerard Alphonse Halle. He was born in Montreal and was given up by Monique and sent to Mount St. Antoine boys home and was taken in by Brother Delphine. Between 1953 and 1954, Lionel was then taken to the United States by Monique's sister Martha (Pelletier) and her husband John Archibald. Lionel went on to serve in the United States Air Force around the time of the Vietnam War. There are four of us children, 2 boys and 2 girls, and numerous grandchildren. Lionel met Gerard once sometime in the 80s where he was given information, but his memory is not what it was. I am wanting to fill in our family tree and be able to show my father who he is and who his family was before he passes, he doesn't even know if his birthdate is accurate. Canada had to make one for him when he entered the US military because they could not find it. This is bothering him more now that he is getting older. It is believed that Jeannine (Gerard's 2nd wife) is still alive as would their children be. Anyone that has any information, please let me know. Even just a little piece will be very helpful in putting this mysterious puzzle together. Thank you