This label did not seem quite right, however, as the green and yellow glaze were not mixed together, and I have never seen a Whieldonware vessel with stippling. In a last ditch attempt to solve the mystery I searched for green and yellow glazed creamware, and look what came up!
These melon-shaped teapots look like a perfect match for this sherd, if it is indeed creamware. These teapots date between the mid-1700s and the 1780s, and, in the case of this one, was produced in Staffordshire. Apparently melon-shaped teapots were all the rage at the time. If this is actually pearlware, then perhaps this design was used on later vessels as well. It is also possible that this sherd is not from a teapot, but perhaps from another vessel that was part of a tea service decorated in this style. Either way, it sure was nice to find out a little more about this unique sherd!