I'm not a man of huge means, however I would consider contributing funds to some kind of legal challenge if that is at all possible.
The Coroner has however made it clear that your testimony does not fit with the initial purposes of a Coronial inquest, however it should be included in testimony in order for the coroner to make recommendations for the future so this doesn't happen again - without your testimony, this can't happen.
As a minimum Dick if you haven't already, you should be taking this directly to the media with a statement near identical to what you have posted here. If the public knew that this was a known Trimble 'condition,' then the fact that this was known should not be ignored. If you believe that you can directly blame the deaths of 6 people on equipment that is fitted to other aircraft that could do the same thing, then people will surely listen and the media should definitely work with it. Go for it! It might take the heat off Qantas and put some on CASA and the ATSB for change!