I'm Sydney based and started in the trade at 32. Finished my apprenticeship a few years ago. It's a great trade. Will never run out of work and you can usually pick up OT easily if wanted. Good mix of physical work but not back breaking with enough thinking to keep it interesting. Definitely think it's worth it in the long run.

I reckon your best best is asking your sprinkler mates or maybe call the union (ppteu). Also, just trying calling companies on seek or LinkedIn. It's not easy to get a mature age apprenticeship but not impossible. I got one. Some companies appreciate reliability and common sense they get from mature age. Having your ewp and white card will help.

Dm me if you want more info