So your closest option for an auto sparkie is Kingaroy; I can see that probably limits your choices to just a couple.
https://www.sptools.com/product-cata...tometer-clone/
We have one of these at work, in honesty it’s pretty good for a quick guess. Quite possible that the mechanical shops in town will have similar or the same. A sparkie should have a carbon pile load tester, this really puts a battery through its paces but being a more specialised item priced into the high hundreds, it’s kind of reasonable to charge people for the results it gives.
https://www.projecta.com.au/products...on-pile-tester