Ulric:
I have plotted my own ping rings for this and agree with the Australian report that the early rings agree with the submitted Malaysian Radar track
We should discuss this and attempt to reach agreement about the ping rings. No conversation can go forth without agreement here.
You plotted your own rings? This means that you calculated distance for each ring using the the BTO data and included the knowledge of the satellite's exact position at that time; did you also compensate for the Earth's oblong shape?
I'm not up for such mathematical gymnastics so I just copied the latest KML version on Duncan Steel's site. Then after being challenged by Nick above I measured the distance between 18:29 and 19:41 rings and the version I'm using matches the expected distance (137nm is close enough to my expectation of 140nm.)
I further checked this against a Richard Cole graphic. I have previously downloaded a drawing labelled "Track_zpse219149d.jpg" (no url) which has the title "Constant Speed path to the final search area" dated may 29th. And the ring plot that I'm using matches this Cole graphic. Although I don't have a url for that jpg I can direct you to page 39 of Richard's data analysis which has a similar graphic with the same information.
Comments from you would be appreciated.