Welcome to the forum Soosa,
Stieglitz Historic park can only be panned in a small stretch in the township area. It's possible to scratch around get a few colors here and there but it has been hit very very hard. You cannot detect in the Stieglitz Historic Park though.
Elaine area is nice and you can detect in Enfield state park. I've been lucky enough to find some nice older crushed vb cans, some beautiful rustic nails, and a couple of newer coins in there, but I have only a very basic detector so I have probably left the good stuff for you. It does get a lot of pressure, but you can find some out of the spot areas.
Where you are located, it would be worth doing a drive around the Winchelsea back roads, and look for old unoccupied homesteads and deteriorated buildings in the paddocks and maybe pop in to the owners house and ask if you can detect them? I have done this with some success and have found a handful of random cool things, and lots and lots of junk, but I did learn a lot about what the sounds meant on my detector. Explaining that you are local, and just doing it for a hobby helped to get me onto some places. Take a nice leisurely drive on a weekend and just ask and ask and ask. Be polite, except the "NO" with good grace, thank them for their time and move on. hahaha But eventually someone's eyes will light up and say "Yeh go for it, would be interested to see what you find"
Think of this local stuff as training, that can be done for a few hours if you have time restraints or just need a fix.
As for finding gold nuggets, I cannot help with that as I haven't found any myself, but if you do happen to come across some, feel free to share the area with a newer prospector like me
erfect:
erfect: :goldnugget: :goldnugget:
Cheers