Hi Patricia,
You could contact Sarah Cowie.  In her study at the iron smelting town  
of Fayette, Michigan, the archaeologists recovered a fragment of an  
alphabet plate.  If I recall correctly, that plate was made of iron,  
however, instead of ceramic.  Dr. Cowie discussed the materiality of  
literacy in a 19th century company town.

She discusses it in her book, The Plurality of Power: An Archaeology  
of Industrial Capitalism
http://www.worldcat.org/search?qt=worldcat_org_all&q=The+Plurality+of+Power%3A+An+Archaeology+of+Industrial+Capitalism

Dr. Cowie is in the Anthropology Department at the University of  
Nevada, Reno. I'm not sure if she has settled in there yet.
http://www.cis.unr.edu/CampusDirectory/EmployeeList.aspx?STAFF=ANTH

Cheers
Tim

On Jun 22, 2011, at 9:55 AM, P Samford wrote:

> I am currently doing some research into alphabet or ABC plates -  
> white-bodied earthenwares produced during the 19th and early 20th  
> centuries and containing alphabets, usually molded or printed around  
> the rim.  We have found examples so far from six Maryland  
> collections and I am interested in learning about other examples  
> found in the U.S.  I am particularly interested in the context of  
> the items-dating, type of site, occupants, type of feature or layer  
> in which the artifact was recovered.
>
> Thank you in advance for sharing your findings.
>
> Patricia Samford
> Director, Maryland Archaeological Conservation Laboratory
> Jefferson Patterson Park and Museum
> 10515 Mackall Road
> St. Leonard, MD 20685