We've managed to pinpoint the building as The Towers which was used by Trinity Grammar as their school from 1913-1923.
|The Towers Image Source: Trinity Grammar School|
Reverend Chambers laying the foundation stone of the new extensions at The Towers, 1917
A newspaper ad from 1890 locates The Towers on a lot of land between The Boulevard, Toothill Street and New Canterbury Road, Lewisham. Research has not been able to establish if this property has been demolished although a large Italianate residence with similar iron lace can be seen from The Boulevard. The original frontage of this property may face away from The Boulevard so it's not easy to see if this is the same house (No 31) with a number of "modernfications".
|The Sydney Morning Herald, Wednesday 5 November 1890, page 3|
Image Source: Trove