Considering that Carlingford is well known to me, the antenna is the wrong type, the very high power transmitters are very close the other options are very low power and a long way away making them unreliable why bother?
Obviously the existing antenna was adequate for analog transmissions on their original channels, so the signal level is not a huge problem.
Kurrajong heights is not designed to cover the far western suburbs not the near inner suburbs.
If it does come down to the need to explore other transmitters, I note that currently myswitch will accept the suburb name Carlingford by itself. Entering that would be enough to give a broad guide to alternative transmitter sites for the OP. (For some reason the myswitch site is not accepting a lot of the actual street addresses within Carlingford!)
The myswitch site does not agree with you, alanh!
Amazon, the online retail giant, is looking for its first warehouse in Australia, with suggestions one site of interest is the Goodman Group's $50 million industrial estate at Oakdale, in Sydney's west. The mega retail "disruptor" already has two traditional-style data centres in what it calls a region in Sydney's west for its Amazon Web Service, and agents say given the usually large warehouses required by Amazon, the new Oakdale site would be the best available.
Oh it's on... a price war between JB and Amazon AUS would be more than welcome.
3 alternative UHF transmission sites available from that area with good coverage according to "myswitch", would be worth a look with correct address put in and or a signal survey with the correct antenna if the VHF is a no go with the existing set up as MLXXX suggests.