This property’s contribution lies in its location on the original Court House Reserve of the Town of York; in the structure’s relation to similar 19th century commercial buildings on King Street East and the south side of Colborne Street; and in the structure’s historical value as the last remaining structure of a row of similar 19th century commercial structures on the north side of Colborne Street.

In the words of the City Planning Division's report on the inclusion of this property on the Heritage Registry:
"Built on land designated in the Plan of York (1797) for a court house, the property was owned by representatives of the Anglican Diocese of Toronto for 150 years. Following the opening of Colborne Street in 1850, the property at 17 Leader Lane/40 Colborne Street was initially developed for a printing shop. The south part of the current three-storey building dates to 1878 when it was completed for the lease holders, George Harcourt, a tailor at neighbouring 65 King Street East, and James Foster, an optician who occupied part of the premises. Beginning in 1884, the building housed the first Grand and Toy stationery store in Toronto and, during the company’s tenancy, a two-storey rear (north) addition was constructed. The property was the long-term location in the early 20th century of D. Smellie and Sons Limited, wholesale jewellery manufacturers, when the third storey was added to the north wing. More recently, 40 Colborne Street was associated with the Tom Jones Steakhouse, which occupied the site for half a century but has now been permanently closed. The property at 40 Colborne Street is identified as a contributing heritage property in the St. Lawrence Neighbourhood Heritage Conservation District Plan (2015)."