A second in the series after a bit of interest in the first- hopefully a little harder.
Firstly you need to identify the object in the listing (somewhere in Wollongong), gather some information from that object and project where GZ will be from the object. Hopefully the clue isn't too hard to locate- if you're from out of town you might struggle a little more but I think you'll get there.
At the base of the object in the image provided there is a plaque. There are a number of sets of numbers. The artist was born in ABCD and died in EFGH. This sculpture was created in IJKL.
GZ can be located at a distance of I(I+L)(I+I+L) metres away, on a bearing of A(B-A).(D+H) degrees from this location.
The maths will get you pretty close- see the hint to narrow things down a little when around GZ. Good luck!