It looks more like a copy to me, the 'pontil mark' appears moulded instead of ground and polished, whereas the base looks ground and polished when it should be moulded. It is harder to tell from photos but the green does not quite look right either, I hope I am wrong...
Copies are regularly found in small and now large Bricklayers, onion vases and this hooped shape, can't say I have seen them in any other shapes.
John