What Should I Do?
If you should find a suspicious item, that may be a UXO, do not touch or disturb it. It's been there for many years, it won't hurt you if you don't disturb it. Contact POLICE they will arrange for military experts to attend and dispose of it.
Unless the UXO was deliberately disturbed (picked up, played with, kicked, thrown, etc) there are no known instances, in Australia, where a UXO has injured a member of the public.