i had , what i thought was a parasitic drain on the battery to find out it was a stuffed battery. the issue started with the flat battery the day after using the car, so i charged the battery and then went back after it sat for three days to find another flat battery. as i hadn't connected the battery, it was obvious what was happening, off to the shop , new battery and all good, no that's not how it works. we all know that nothing is that simple, after connecting up the new battery i decided to just check that the alternator was working and yes it was working, it was working to much actually, charging at 16.9volts," i think this is the reason for the battery dying " even i know that's not right. now the real issue, i have 3 spare alternators or should i say had. the issue with the alternators is the brushes, and the bearings, but that's another day,
where the brushes rub on the rotor in the alternator on the brass piece on the shaft had very large grooves on the outside brush, this was on 2 of the alternators and that brush had all but worn away, whilst the other was fine. is this piece replaceable or is it the hole rotor that has to be replaced, also is the regulator still available as i don't seem to be able to find them in Australia. so as a warning if you have alternators as spares remove the back cover and visually look at the brushes and the area that they contact.
If you’re talking about the commutator (the brass/copper part that the brushes contact), I’m pretty sure that’s not replaceable. Regulators should be, but might not be easy to find. There was a company in the US that sold alternator parts, but they didn’t even ship to Canada.
The regulator I got was one of these https://www.onlinecarparts.co.uk/hc-cargo-25072361.html which fits the Magnetti Marelli alternator fitted to the GEMS. Although a .co.uk website, the company are actually based in Germany so may ship to Australia or just Google the part number and see if you can find a local suppler (it is also used on a number of other cars so may be far more common than you think). You can't replace the commutator though and the only way you would be able to get a complete rotor would be from another alternator. In which case you may as well just fit the other alternator.....
If the slip ring is worn, a decent auto alternator shop can replace the brass rings.
I had some done on a big CAV alternator for the boat by a shop in Vic, now closed due to the owner passing.
Having said that, and you being in Tazzie, there is a slight chance that you can find one there.
Start with these guys. If they don't do automotive units I bet they know who does!
https://electrorewinds.com.au/
I know there was a good shop in Melbourne and being full of grey haired men, they can do just about anything.
I will ring my mate there and see if he knows if they are still trading.