O’Neill possible ownership
It appears that the O’Neill Brothers owned the Campbell’s former property on Duke Street, leasing it to James Gordon. It is not clear who owned the house while Thompson Smith was a resident. The beginning and end dates of the O’Neill Brothers’ ownership of the house are approximate.
The O’Neills were notable merchants and auctioneers in the town. Peter J. O’Neill and Terence J. O’Neill came to York/Toronto from Dublin at different times. Terence served in the British Army, taking a veterans’ lot in York in 1829. He started a mercantile partnership with Patrick Burke. Peter emigrated to Montreal in 1833, running a dry goods business until the 1838 rebellion drove him to York. The brothers began a partnership in 1843. Terence was active in local politics, allying himself with reformers.
By 1861 Terence had been appointed Inspector of Prisons, while Peter and his son John moved to Port Huron in the United States. While in Port Huron, Peter founded another dry goods store. In 1883 John was elected mayor of the town.

Sources:
- Biographical Info – Western Historical Co – History of St. Clair County, Michigan– 1888 – p. 589 (https://books.google.ca/books?id=lKnQAAAAMAAJ&pg=PA589&lpg=PA589&dq=Peter+j+O%27Neill+port+huron&source=bl&ots=2ZvaVH5W3q&sig=L-3nCwY8YI8rlNcP4CKZy-MfRO8&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMIz-j5_rjixgIVAWg-Ch0DtQme#v=onepage&q=Peter%20j%20O’Neill%20port%20huron&f=false)
- Biographical Info – Dictionary of Canadian Biography, Terence Joseph O’Neill (http://www.biographi.ca/en/bio/o_neill_terence_joseph_10E.html)
Ad – The Toronto Examiner, 28 June 1843