Just got this in a mixed lot and can't seem to identify it. It looks to be 1775 and has a reverse crest similar to a Virginia halfpenny but the legend doesn't match up. Any help would be appreciated. Thanks!
What you have there is a contemporary counterfeit of a gold guinea. The gold coating on yours has largely worn away. You can see an authentic example here: https://www.bullionbypost.co.uk/collectible-coins/guineas-gold/1775-george-iii-guinea-gold-coin/.
Contemporary counterfeit as NOS said. Very interesting and very collectible in its own right. In the 17th and 18th c it was believed that as much as 50% of circulating coinage was counterfeit