Here are the Pattons that I have found in Lovell's directory for 1842:the name of the person foll. by the street name
Paton, Thomas, inspector of Branches of Bank of British North America, Great St-James St. John Paton, tavern, St. Giles near Water St. James Patton and Co., wholesale china glass. McGill St. Patrick Patton, labourer, St Constant, near Dorchester St. William Patrick, grocer, St-Charles Borromée near Crai St.
In 1843, the latter's business is said to be at the corner of St-Maurice and Inspector St.
I did not check the marriage record data for William and Elisabeth since you seem to have done it.Avail. on microfilm only.