Judging by the reverse, the outer rim around miss brittania seems to give it away as a george I halfpence of 1719-24. Still, the bust on the obverse doesn't quite look like George i-- normally George has a kind of pug nose whereas your bust seems tohave more of a beak like nose. Also the head doesn't seeem quite right for these. British counterfeit halfpence were common but not until AFTER George I, so if this is a contemporary counterfeit of George I, I would think that is pretty scarce. Then again, can't discount that wear and corrosion have wreaked havoc on George's bust. Would be interested to see what others have to say.