I have several rolls of 1960s vintage Kodachrome still in the boxes (and metal cans, I think), but I can't put my hand on them instantly (still in boxes from a move five years ago). The auction site seems to have lots of 828, though the sellers are pretty proud of a lot of it and their quoted shipping may not be the same to Australia.
FWIW, you can make 828 film from 120 (more easily, in my experience, than rerolling 35mm, especially if your camera has the feeler finger at the corner of the film gate). Just cut the roll 35mm wide on the 6x4.5 framing track edge, keep the backing (trim the leader for length and shape) and respool to 828 spools (which you still need). You'll get 16 frames (instead of the original 8 or 12) with a fairly wide space between if you use the red/green window, or if you have a camera that stops advance with a friction wheel like my Bantam RF, you'll get 18 frames with normal spacing. And yes, the film and backing will (barely) fit on the spool, partly due to modern film being thinner than what they had in the 1950s when 828 came out. The off cut can be cut again to make a roll of 16 mm non-perfed (for Minolta 16 and similar, long enough for two cartridge reloads) with no edge markings to intrude in your images.
Bantam RF, .EDU Ultra 100 (cut from 120), Parodinal 1:50
If no one pops up with spools on your side of the planet, send me a PM and I'll see if I can't dig up a couple rolls and find out what they cost to ship from here to there.
Your Bantam Special, if everything is working correctly, should do at least this well. Good luck!