On the subject of those C0 to C5 $25,000 Finals at Menangle...
...Under 3. HANDICAPPING PENALTIES GENERAL
Rule 3.1 (b) (iv), covers them.
Although probably better read in the context of the entire section I can't get the damned thing to copy & paste for some reason so, to save everyone the trouble of looking it up, the specific section reads as follows...
(iv) a special race approved by the Controlling Body with no stakemoney restriction for Pacers classified C0 to C5 (inclusive) or for Trotters classified T0 or better.