Hi Daryl,
Good question an area that is not much covered. 1981 circulation coinage was struck at The Royal Canadian Mint, Ottawa. Whilst set coinage Proof/Mint was minted at The British Royal Mint.
The 2 examples that I have.
1981 Mint set
Coins of all nations New Zealand assume circulation coinage.
From what I can see, I would say yours (nice example) of a circulation strike. Oval holes
Thank you Jcler001 I found another 1981 20 cent. And they look the same. So I think you are right a circulation coin. It is a really nice looking coin.