I think I have it! Paul had it spot on and Colin was going well with his idea as well.
When you use Google Earth to the middle of Tony's picture (call him Sherlock) 27°27'43.71"S and 153°02'06.91"E and zoom in on the text written on the road - it says Water Police!! Look to the very top of the old pic and I think that is a Falcon Patrol car (but I wouldn't be good on my models).
So, back to the idea that it was a compound. You can also see that there is still a chain link fence in place along with the 2 sheds in the top corner of the original picture still there today - which shows it was not an aerial photo but taken from the bridge.
Anyone in Brisbane confirm that the building on the water is/was the Water Police - there is a date by the look painted on the road so they may no longer be there.