I got a '43' also. At 12.5 mm, these little ones remind me of Lauer tokens. The last date number is crooked to. https://en.numista.com/catalogue/pieces13826.html
I know I have a couple but not sure of the dates. Also have 1/3 farthings. Weird denominations are fun.
It is known as the Three Halfpence, used in the colonies they never circulated in the UK, they also resemble the Maundy issues. Here's the Penny, Three Halfpenny, Two Pence, Three Pence and Four Pence around a Crown.