Hi Rob nice work,
I was wondering if your geo might be Optus b3 or Optus c1? Orbitron shows a few near that location. It's a shame your series of images didn't last a bit longer some of those satellites are eclipsed at that time as well. There is an older thread about Optus b3 here that you may find interesting, it has some good information and links to geo tracking programs.
http://www.iceinspace.com.au/forum/s...ad.php?t=16246