Hi Rosewater, Welcome to Photrio!
I'm not sure where in Australia you're located, but all of my "found film" came from a local second hand place in Tyabb, Victoria. One dealer there bought old cameras and, if there was film inside any of them, he gave them to me to be developed. I can give more details of the location if you're in the vicinity.
I'm afraid any film I have that might have fit your requirements was developed the moment I acquired it. Like pentaxuser, I'd probably have had trouble relinquishing it anyway if I didn't wind up with the negatives and/or prints afterwards and I'd also be somewhat concerned about privacy issues if they were to be displayed publicly. That being said, your project sounds intriguing and I'd love to hear more about it!