John,
They have never been recorded on the mainland, nor in any reputable references reported them on the Cape either.
I am well aware of the "Australian" Islands just off the coast of PNG eg Sabai etc
NO Records of Leiopython are known from Australia or any of its Island territories.
If you read my post I did not make an exception for the torres strait islands as they quite simply are not recorded there.
D' albertis are a upland species restricted to closed forest and rainforest in the Southern Parts of their range (generally the southern form is found below the Owen Stanley Range).
In the 2 most recent publications covering Queensland's herpetofauna they were excluded both times, along with 2 varanid species that are yet to be confirmed within Australia (finschi and doreanus) by any Australian Museum or Parks office.
Regards,
Scott Eipper