Thank you for all the welcomes and help.
After making my original post here, the bloody bird has not shut up crowing! It's almost like he knows we've figured him out.
I've phoned the local council for advice. They were aware of the dumped chooks down by the railway tracks, and are going to bring around a cage so we can catch our friendly boy & have him taken elsewhere. If we were on a decent sized property, we would have no problem keeping him, crowing and all. However, we're in the middle of a residential neighborhood on super small housing blocks, and most defiantly not allowed to keep roosters. Our son will be most upset, but we may look into one or two hens if we can find nice, quiet ones!
I really appreciate all who have commented, and it's nice to know that a community like this exists. We are hoping to buy our own place next year on a 2-3 acre block, and will most definitely get a flock of chooks then.