Ned-
 
What is the condition of the sherds?  Are the surfaces smooth? Do they
have little crackling marks where the glaze may have been before removal?
I find it hard to imagine glaze being ground or flaked off without leaving
tool marks!  Also what is the time period of the site and assemblage?
Late nineteenth and early 20th century assemblages could contain
"blanks" that companies sent out to people, particularly women, for
hand painting that would be returned to the company to be fired.  Rather
late for creamware though.  More info needed...
 
Tim Scarlett