Hi BB,
Having had a bit of experience with Villiers engines and coils, the coils do tend to be the main culprit of "failure to proceed". I have not had a lot of luck procuring replacements in Australia but there are some suppliers in England that do have replacement ignition parts. Meetens, Villiers Services and Villiers Parts are the ones that I can think of immediately. Whilst I do not endorse any particular supplier, to give you an idea of what is available have a look at:
http://www.villiersparts.co.uk/ignition.htmlI know that the three companies listed are happy to send items to Australia and that it pays to get a quote for parts from each of them as prices vary from place to place.
Hope that this is of assistance in your quest for parts.
Regards,
Sir Chook