The Mimico Heritage Study, part of the Mimico 20/20 planning process, has been posted to the City of Toronto website:
Click on the link above to access the PDF file.
It makes for great reading.
You may also wish to have a look at this TOBuilt list of 116 buildings that are described as older than 1850.
Among those buildings is 28 Daisy Avenue in Long Branch, built in approximately 1850.
For 28 Daisy Avenue in Long Branch, the year 1850 is a possible year of construction. What we know for sure, as I understand, was that the builders bought the land in 1847 and the house was constructed before the 1852 census.
More details about the latter property can be found elsewhere on this website.
These house stories bring to mind this recent article about the restoration of a historic house in Scarborough.