Regret to say that James was not born in Magog. From the names mentioned, this appears to be the Roman Catholic branch of the Billings. Your James was possibly, and I repeat possibly, born in stanstead and baptised there as well. He is most likly the son of Henri Billings and Stephenie Allard who are living in Stansead.
In Magog there is a Onésime Billings and Alda Robitaille who baptise Alice-Irène 31 july 1904 andCécile-Lucienne 9 Dec. 1906.
Your James aka Onésime may have a sister Gertrude Billings who marries Arthur Garceau at Stanstead 1 Aug 1905.
The above apply if the James is Roman Catholic.