Thanks for the comments guys.
One must always becareful when just looking at the images and then making an analysis (especially just 2 images!) What the photos don't show is the massive rain and hail curtain just to the left of the storm. In fact, on the first image we were receiving 1-2cm hail at the time (albeit hail falling from the overhang of the updraft). The separation between the updraft and downdraft of the storm was incredible - something I've not personally seen before in Australia. If you see radar, you can see the main downdraft, and then the very large notch/hook of which the meso is sitting in. Towards the end it lots its shape, and then a larger black call develops just south of Marburg which I suspect was the storm letting go (and tending more HP).
This particular supercell was most likely a classic, going to a HP towards the end and dying.
Shear was certainly strong enough for supercells (25-30 knot SW @ 500mb, and a 20-25 knot NE at the surface thanks to the seabreeze), but I do agree I didn't think that the structure would be quite like that!
The inflow was particularly impressive, even when the main rain/hail core was just 1-2km away, the inflow was solid. At times, inflow gusted close to 30knots with small twigs and branches being broken off trees. For a short time, a small part of the meso was rapidly rotating but it didn't do anything further - I noticed Doppler had a small 70-80km/h in and outbound at the time side by side when this occured.
AC