That is the silly thing about NSW system. It relies on the person filling out the form and sometimes they are not well eductated and have little idea. It should be a prescribed set of vehicle definitions to choose from. In Rodney's case it should be Make: GMH, Model: HZWM70, Variant: Holden or Holden Sandman (or Kingswood or Premier or whatever if it is one of those), Shape: pvn (or ute or sedan or whatever). A lot of stuff is out there is also registered pre blue slips and under different systems as well so there is no consistency. It looks like they have called Rod's van as a 1977 model HZ too, where is is a 1978 model HZ.
None of this really matters I suppose, as all they really need is chassis and engine numbers, but it'd be nice to get it right!