Seeing as I was using a light filter (Astronomik CLS (EOS Clip)) I went straight for targets with nebulosity. The first thing I noticed was that everything comes out RED, actually subs look bluey-green but the stacks look red. So I tried toning it down as much as possible post editing in CS6.
What I have achieved is a lot more nebulosity than previous attempts, which is also due to 240 sec exposures, but this time the St George Hospital flood lights and Big Smoke Sydney City didn't drown out my subs the way they used to. There was a also a fine layer of cloud and moon light scattering.
Thanks for looking

comments always welcome
Canon 60d
Astronomik CLS (EOS Clip) Light Pollution Filter
Orion Field Flattener
240sec exposures
800iso_36min_9frames
Sky Watcher ED80 Pro Gold Edition
Sky Watcher HEQ5
Orion Star Shoot Guider on a 50mm Scope
Backyard EOS Software 'Camera Control'