I have 3 of the 1972s and one is clearly EF

My 1966's

It's a high grade one (EF/AU) like all my 1966's except my worn 20 cents. I don't have a separate photo of it sorry.
Wrekkdd - The 1972 Australian 5 cent coin had the lowest mintage of any date with just 8 million minted, compared to a usual figure of 30 - 150 million coins per year. They are fairly scarce now and it took Machinmachinman a while to find one in his Aussie circulation coin challenge.
Not sure about significance of the 1966 though, it wa sthe first year and minting from London also helped out with the Canberra minted coins.
Edited by Princetane
08/22/2022 2:30 pm