Salvador Gutierrez and Gertrudis de Vera

I have not been actively researching for some time now, but recently I came across a long-lost cousin of mine who found her father in my genealogy database online and we have reconnected. Her father left Mexico as a young man during the Mexican revolution, with a handful of photos of his family, expecting never to see them again.

He never did, but his daughter found us ninety years later and we found some precious treasures including a photo of my great-great-grandfather from 1907.

http://ramosfamily.org/nextgen/getperson.php?personID=I374&tree=RamosPinedo
http://ramosfamily.org/coppermine/displayimage.php?album=20&pos=34

This reconnection with this long-last brach of my family has led to me reconsider trying to break through a brick wall that I ran across a while back.

The furthest ancestor in this Gutierrez line that I have is a certain Salvador Gutierrez married to a Gertrudis de Vera in the mid-1700s. I have several children for the couple baptized in Tlaltenango, Zacatecas beginning in 1738, but I have been unable to find their marriage record (and thus have been unable to get back another generation):

1. Juan Antonio GUTIERREZ VERA, b. 1738, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
2. Joseph Maria GUTIERREZ, b. 21 Sep 1739, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
3. Juan Manuel GUTIERREZ, b. 29 Dec 1741, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
4. Gertrudis Dionicia GUTIERREZ VERA, b. 3 Nov 1742, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
5. Juan Antonio GUTIERREZ, b. 18 Apr 1743, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
6. (Jose) Blas Antonio GUTIERREZ, b. 18 Feb 1749, El Durazno, Tlaltenango de Sanchez Roman, Zacatecas
7. Juana Maria Francisca GUTIERREZ VERA, b. 3 Jun 1753, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
8. Vicencia Theodora GUTIERREZ VERA, b. 4 May 1755, Tlaltenango de Sanchez Roman, Zacatecas, MEXICO
9. Maria Regina GUTIERREZ VERA, b. 1735

There is a couple that intrigues me in the records, though the grooms surname does not match whatsoever. Any leads or suggestions would be greatly appreciated.

SALVADOR SANDOVAL
Male
Parents:
Father: FRANCISCO SANDOVAL DE FL.
Mother: JUANA PONCE
Marriages:
Spouse: ANA DE VERA Family
Marriage: 13 SEP 1736 Tlaltenango De Sanchez Roman, Zacatecas, Mexico