>I am familiar with metal coffins with glass plates or windows over the face,
>which seem to have been popular ca. 1860-1880, but has anyone encountered
>similar windows associated with wooden coffins?
>
 
Many years ago I salvaged three coffins from a construction site.  The
excavation conditions were less than ideal but one coffin definitely had a
glass plate over the face.  The burial appeared to date to the turn of the
century ( I can't find the article this morning).  The site is located in
Medicine Hat, Alberta, Canada.
 
The reference is
Finnigan, J.T.
1981  St. Barnabas Burials: Salvage Excavations at a Late 19th Century
Cemetery. Na'pao, 11:41-48.
 
Napao was published by the anthropology and archaeology department at the
university of Saskatchewan.
 
Jim Finnigan
Western Heritage Services Inc.
Saskatoon, Saskatchewan
(306) 975-3860
http://www.westernheritage.ca