What they have found is that the double rim is due to a smaller obverse die –that of the dollar coin! We know back in the year 2000 the Royal Australian Mint made a mistake and paired the mob of roos dollar reverse with the 10 cent obverse creating the now famous Australian mule. For those new to this terminology a ‘mule’ is created when 2 dies are paired that weren’t meant to be used together. Now what we have here is a New Zealand 2004 10 cent mule. Which sees the dollar coin obverse die paired with the regular 10c reverse die.
It’s been determined that the new mule is only found in circulation coins and these were struck by the Royal Mint. It is not found in mint sets which were struck by the Royal Australian Mint. Our member showed examples at the monthly meeting of the Australian mule and the newly discovered New Zealand mule.