Hi Grievous,
There's a pretty good Golden Oldies scene around Sydney. It seems to be focused mainly in Sydney's north but there are clubs everywhere. There's no formal competition as such. They're just invitational gala days where you play against every team there on the day. Unless it's a relay big day then there's a draw. If one team doesn't have the numbers, somebody just fills in.
It's a lot of fun and pain and getting used to the coloured shorts is interesting. I believe every game ends in a draw. The main thing is everyone is there just to have fun playing the greatest game there is.
I could rattle off a whole lot of names but if you let me know where you are I could hopefully point you to a club.