Hi. There's only one common blender made by Braun, which has a triangular jug in either glass or plastic, but the locking ring and gasket are the same. It'd be a 4184, either a MX2000 or MX2050.
Auckland has a Service Centre:
Key Service Ltd7D Echelon Place, East Tamaki, Manukau City Auckland
P.O. Box: 38569 Howick
Manukau City
Phone Country Code: +64
Phone: 09-916 0960
Fax: 09-916 0970
Service for: All products
Otherwise, you can locate Service Centres in Australia.