Other interesting callsigns:
3AK (known on air as SEN) - named after Akron Tyre Company (original licensee)
3AR (now 3RN) - named after Associated Radio Company of Australia before the ABC took over all Class A licenses in 1932.
2MO Gunnedah - named after Marcus Oliphant the station’s founder.
2SM - named after St Mary (originally owned by the Catholic Church)
2GB - founding theosophist Giordano Bruno (nothing whatever to do
with Grace Bros!).
3AW - Allan’s Williamson’s: Allan’s was a music store in Melbourne, still going strong today. Williamson’s was a live theatre chain in Melbourne.
7ZR (now ABC AM Hobart) - Zeehan-Rosebery two towns in Tasmania nowhere near Hobart! 
2COW - Casino’s Own Wireless.
3YB - Young Brothers, they originally had a mobile radio studio on a train and travelled across Victoria stopping off in towns that did not have a radio station and doing temporary test transmissions. As more stations came onboard in regional Victoria, Jack Young bought the licence for Warrnambool and named it 3YB.
4IO for Radio 10 was an unusual one.
At the same time some of the ABC TV call signs started to get a bit cumbersome; it was OK when it was just 4 letters but then in some states with the opening of several translators, they ran out of letters - so we got ABMIN 10, ABCLQ 7, ABAAQ 11, ABPHW 7 and more - video
That’s the popular line of thought, but I believe (from good authority) that 2SM was actually named after St Marks, not St Marys.
No, Wikipedia isn’t my good authority, but they actually have it right.
3LO was named after 2LO in London.
2UE was named after Electrical Utilities and was originally 2EU but the letters got swapped. I think on early radios the call sign sounded like “Who are you?”
2BL was originally 2SB but changed because it sounded too much like rival 2FC.
Stations with links to the Labor party had ‘K’ callsigns e.g. 2KY 3KZ 5KA 4KQ etc. No idea what the significance of the K was.
3UZ and 3XY were just random letters. Given that 3XY was owned by Frank Thring Snr (Efftee Broadcasters) I’m surprised they didn’t go with 3FT but 3XY was a better choice.
Karl Marx? 
Not all Labour party stations had a K. Take 2HD Newcastle
For what Wikipedia is worth [citation needed], 2HD did not come under control of the Labor Party until after World War II. Its call-sign was determined well before then (after station founder Harry Douglas) when it launched in 1925. 2HD - Wikipedia
Another station: 3SR in Shepparton, which I’d always assumed was derived from “Shepparton” or even “Shepparton Radio”, was actually named after station chairman Staniforth Ricketson.
It was originally 3WR in Wangaratta but changed to 3SR in 1937: 29 Jan 1937 - 3SR. SHEPPARTON, TO OPEN ON MONDAY - Trove
PTV - correct.
Recently mentioned on the Australian transmitter/tower FB page. You saw it there?
Not familiar with that page, possibly goes back to the Vega days when I saw it.
2SM is named after St Marks in Drummoyne. The parish priest Monsignor Meaney started the station.
And before 2SM started the Sydney Archdiocese rented time on 2UE.
It looks like 4 TEN but that call sign was never used on air
Speaking of 4IP “Stereo 10”, the tribute stream is supposed to be launching on 10 August.
EDIT: 10.08 on 10/8. I just got it.
Over the last few months I have been listening to the Game Changers: Radio Podcasts. It is hosted by Craig Bruce, the former national head of content for Southern Cross Austereo. It features intimate conversations with those who have known success and failure in their radio careers.
My favourite ones that I have listened to so far are Andy Lee, Hamish Blake, Amanda Keller, Robin Bailey, Jamie Dunn, Richard Stubbs, Mick Molloy and Eddie McGuire.
Would suggest the ones with Tim Blackwell and Marty Sheargold too
Among the many other interesting things on display in the fairly new “Milk Bar Cafe 2223” at Mortdale in Sydney’s South, this 2UE “Show Guide '76” bag which also doubled as a promotion for a station competition giving away cash and colour TV sets (which back in 1976, would’ve been a pretty good prize):
That milk bar is basically on my doorstep; I didn’t see that during my visit a couple of weeks ago (before they officially opened, admittedly). I did see plenty of memorabilia from 70s and 80s rock acts, though, and I think there was some 2SM stuff as well.
Stereo 10 now up and running - Hint: click on the car radio! (took me a while to find).
I remember live broadcasts being done from the street entrance at bottom of the members stand. I think it was 2GB.