The local requirements are in a state of flux with the changeover to manufacturers' flight manuals.
P2T2's problems relate not to the production of base performance data ... rather the production of line crew usable data. If he is tied up with an RPT operation, CASA's requirements get a bit specific.
If you would like to send me an email, we can then make contact by phone, perhaps, and I can offer suggestions. Certainly there is a number of chaps in the local region who are quite acceptable to CASA for the production of such data ..... even me.
Some of the chaps who do this work locally are interested pilots with no engineering background and they seem to do a reasonable job ... if you have an interest in the subject matter ... you could do well to get stuck into and learn the trade the hard way ....... the rest of us would be only too happy to give you a bit of a hand ....