Thanks for the thoughts everyone. I think the other main issue is we have two kids fast approaching university age and both want to go. Without PR, I think Uni in Aus would be widely unaffordable as international student rates. Leaving them both here isnt something I am comfortable with. There are few and far betwen internation sponsored police recruitment for police officers and I would need to take drop in rank and go back on the streets as it where, so realistically, I dont think that's an option so close to my possible UK retirment age. So it looks like we are going to stay put until I retire in 5-6 years and both kids are adults and out of university. That will make me age 50-51. I don't know how long we can stay in Aus then as either temporary workers or just to travel, but it's something we will definitely look to do.
Thanks everyone for the advice, and for those younger than us and thinking about it, don't wait to give it go! We had no choice as my son had cancer at quite a young age, thankfully he is well now, but it took us away from considering a move when we were at the right age.