Not CASA AD's
Flopter,
Your first misconception is that this SIDs is only a CASA AD in so far as it mandates that you comply with the actual SID's document which comes from the Cessna factory. The SID's document states that for compliance it assumes that all of the Cessna service bulletins and FAA AD's have been complied with before you start the inspection. For most light aircraft maintained in Australia under CASA Schedule 5 this is not the case so you are behind the eight ball already. By complying with the inspection you are actually dragging your aircraft up to speed maintenance wise. Additionally you are raising the level of your own safety to acceptable standards. My advice is pay for an inspection only and then make a decision as to the economic viability of having any defects repaired. You may have a nice clean airframe and get away with it but don't expect to get out of this for under at least $15-$20K.
Groggy