I reckon if you don't need them for registration, maybe get it reg without, then fit these, which may or may not suit Oz officialdom but would have to work. Fewer holes you have to dig the better.
Beetle and Bus seat belts, newly designed by Wolfsburg West
Finally, seat belts they way that they were meant to be! Our
newly designed seat belts are a spot on match of early version
seat belts offered by Volkswagen. Such features include black
enamel coated receptacle and Wolfsburg logo embossment.
We currently have the three-point version in stock, with the
two-point version to follow in one week. Please follow the
below links for view the 3-point style:
Black, part # ZVW20ABK, $32.00 each
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=ZVW20ABK
Grey, part # ZVW20AGY, $32.00 each
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=ZVW20AGY
Tan, part # ZVW20AAL, $32.00 each
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=ZVW20AAL
Red, part # ZVW20ARD, $32.00 each
http://www.wolfsburgwest.com/cart/DetailsList.cfm?ID=ZVW20ARD