1798 One Cent contemporary counterfeit...or something else?
I found a coin recently on an archaeology site and am looking for any information on it, as it certainly doesn't appear to be a mint-struck coin. The coin in question is dated 1798 and the pattern is that of a Draped Bust one cent. However, it is only 26mm (it is missing the beaded rim), weighs 2.1 grams, and is 0.5mm thick. The measurement differences are not due to wear. I've included photographs (or rather links to Google photos; I don't seem able to embed images in the post), though they are rather poor, as the coin has proven difficult to photograph due to the low relief and general "mushiness" of the features.
I suspect that this is a contemporary counterfeit, though I cannot imagine anyone that had ever held a real one cent being fooled by it. Perhaps it is along the lines of so-called "evasion coins" of England? A 1773 counterfeit British halfpenny was also recovered from the site, though those are common enough.
Thank you for any information or insights!