I am guessing British Half-penny...any ideas, date range, etc???

[Jolly Mon]

1672-1679 Charles II Farthing

I found this ruined thing in a salt water environment today. Copper composition, 21 mm diameter.

It looks like to me it is Charles II farthing minted from 1672-1679. Any ideas? opinions?

Thanks in advance.

 

[Iron Patch]

Yep. You got it.