Spouse of Olga:

I think you meant to put the following URL of the folder containing your wife's ancestors' information:

http://www.nuestrosranchos.org/node/16141

Being in the midst of compiling genealogies of the oldest families in Tlaltenango, I can tell you that CASAS is among the names of those families whereas Diaz de Leon is not, though there are sporadic DIAZ and LEON in early Tlaltenango. As you probably already know, the IGI does not have the parents' names for the wedding that you mention between Ysidro and Apolonia, but the Tlaltenango church records are quite well kept (if often written in bad penmanship).

I would suggest you order the film (0443973) from your local family history center, or check in the Films database to see if a member has it and would be willing to do a lookup for you.

There is a Maria Apolonia Casas born in Colotlan, Jalisco (near Tlaltenango) around the right time to be the same Apolonia Casas:

MARIA APOLONIA CASAS RIVAS
Christening:
14 APR 1827 San Luis, Colotlan, Jalisco, Mexico

Father: GUMESINDO DE CASAS
Mother: MARIA RAMONA RIVAS

Batch No.:C602868 Film No. 0443678