You're right on that regard in that a literal F7 was never ordered new by any Australian railway (although the VR S/CR GM/NSWGR 42 classes were essentially a cutdown and stretched F7 more suited for our smaller loading gauge and lighter track.). However, having said that, two F7s did in fact see service in Australia - two were purchased second-hand from the US Western Pacific Railroad in the late 60's/early 70s by the Mount Newman Mining Company for use on construction trains on Mount Newman's iron ore line in WA's Pilbara region.
Once the line was opened they were delegated to back-up power and service trains for a while before being withdrawn and preserved by the late 70s. As I understand one is on static display in Port Hedland while the other was formerly in the custody of the now-defunct Pilbara Railway Historical Society who restored it to working order for occasional tour train use on the iron ore lines. I have no idea what has since become of that loco though since the PRHS shut down and disposed of their assets.
Anyway, I know there is an old fairly accurate Paintshed reskin of the Auran F7 in the Mount Newman livery on the DLS as 04 content if anyone is interested, as shown below:
EDIT: the reskin was done by John_SB and it's KUID is kuid:60318:3003.
Had alook at google earth, there is photos of the F7, she looks very sad
Cheers,
Patchy
