http://www.casa.gov.au/download/orders/cao40/400201.pdf
cao 40.2.1
12.3 Where an instrument rating has expired for a period in excess of 12 months, an applicant may qualify for issue of a rating by passing the instrument rating test applicable to the initial issue of an instrument rating. Initial issue means all navaids again as well.
if you have done your me-cir this month i would assume you were up to speed with this section of the cao's!
why dont you just renew it?