not sure on the history of WZU i'm pretty sure it's an ex aero tropics shrike.
the rego YJP is now for a 690A, can't seem to find any more info further back
...edit
found this link in a casa change of mark form;
"WZU","AEROCMDR","500-S","3060","1/12/2001","YJP","LIP-AIR PTY. LIMITED T/A AERO-TROPICS","PO BOX 147N","","CAIRNS NORTH","QLD","4870","","","","","","","",""
original file,
http://www.casa.gov.au/wcmswr/asp/ca...ates/Cmark.csv