I was surprised to see that one longtime brand I associate with my earliest days playing around with radio, Barker and Williamson, is still thriving – and even better, still providing the product I associate them most closely with, air wound coils, specifically the Miniductors.
There’s a list of the types they have available here. They’re not cheap, but they are convenient. They don’t appear to have a local Australian distributor. They do sell an attractive looking 13-42pF butterfly variable capacitor for US$25.