A WILLIAM AND MARY LIDDED FLAGON

For a similar see the Worshipful Company of Pewterers of London Supplementary Catalogue, 1979, p.33. fig. 201.
It is interesting to note the similarity between the shape of this flagon with both lidless tavern mugs of the period (see Christies Little collection, May 2007 lots 124-126) and Scottish lavers of generally later date.