James,
 The Center for Archaeological Research, UTSA, San Antonio, TX excavated
21 burials in Bastrop County, of which eight were glass fronted. Some of
the date were unknown, but the ones identified were from 1891-92. For
full details see:
        Taylor, A. J., Anne A. Fox and I. W. Cox
        1986    Archaeological Investigations at Morgan Chapel Cemetery
(41 BP 200), A Historic Cemetery in Bastrop County, Texas. CAR, UTSA,
Archaeological Survey Report, No. 146.
You can contact the Center at [log in to unmask] or
http://www.csbs.utsa.edu/org/car/index.htm
 
Waynne Cox