John the houses are stunning. I would give my eye teeth for either of them. I can't help with the identification though I'm afraid.
I'm very very sorry to say that knowing how little is thought of our beautiful historic buildings and the destruction that has taken place over the years, I would not be surprised if they are no longer standing. The other possibility is that they have been "modernised" and are no longer recognizable, or they may be surrounded by new builds or high rise and no longer have the lovely gardens your ancestor laid out.
I hope I don't sound too gloomy, and nothing would make me happier than to be proven wrong. It's just that the chances of someone recognizing them is quite slim. I hope for a miracle though.

Is there any way you can narrow down the location? Perhaps tie them in with locations where he was living when his children were born? Have you found any mention of him on Trove? Obituary perhaps? Were there any other photos with these two, which may give something more for us to go on?
Looking at both, the styles of the houses could fit in with both NSW and Victoria, which is such a large area.
