Compare the very similar ewer, with cover, in the collection of The Art Institute, Chicago, illustrated by Margaret Medley, Yan Porcelain and Stoneware, London, 1974, pl. 10. This type has been dated to the first quarter of the 14th century, and according to Medley, 'the slip appears to have been roughly applied to conform broadly in outline with the proposed elements and has been tidied up with some careful tool work.'
Another example, with elaborate detailing is illustrated in Sekai toji zenshu, Tokyo, 1981, vol. 13, p. 56, no. 42.