Agree XXX,
South of Perth, once clear of the MIL R airspace, FL180 is LL of E.
This is the closest to Jandakot if ya want to go 'up'.
E = LL FL180 seems to be the standard for the remainder of the country...I would think....
(Don't have all the charts either...)
Perth VNC, ERC Low, refer.
Cheers