G'day, I don't collect Irish coins, but I have a special interest in English coins of that era.
The obverse field looks abraded, but in spite of that, the effigy shows no sign of wear or damage: I'm looking in particular at the hair, the wreath, the eyebrow, and at the folds of fabric in front of the neck.
It has been explained to me that fields sometimes lack the mirror finish one hopes for, not because the coin has been cleaned, but because the die has been cleaned abrasively.
I'm wondering if your beautiful halfpenny might be an example of that ?
It's not common for copper coins to be found in such enviable condition: it's a beautiful piece. And well photographed.
Peter