After nearly a dozen years of looking for clues, I’ve finally broken down a wall that had perplexed me. My 5g grandparents, Eugenio Rufino Galván and María Dolores Fernández, lived in Sierra de Pinos, Zacatecas, during the last quarter of the 18th century. They also lived part of the time in Real de Catorce, Slp. They first appear in the Pinos parish records on 16 Mar 1776, when their children, Juan Joseph and Maria Josefa, were confirmed. Maria Dolores Fernandez died and was buried 26 Feb 1793 in Pinos; according to her burial record, she was originally from Silao, Gto. Eugenio Galván married a second time, to Maria Micaela Cordoba, on 10 Jun 1793, in Real de Catorce. According to his IM, he was about 53 years old (b. 1740) and he was also from Silao. 
I started dredging the archives of Silao looking for any clues. Though I found some Galvan’s and plenty of Fernandez’s, I could still find no sign of Eugenio Rufino, which is a really unique name. So I put this couple on the backburner. Every once in a while, I’d take them out and rummage around: there was another couple living in Pinos named Felipe de Santiago Galvan and Juana Francisca Xaviera Delgado. They were married 14 Aug 1738 in Guanajuato: he was from Silao and was the son of Bartolome Galvan and Josefa de Chagoya. They were old enough to be Eugenio’s parents, but I could find no contact between Eugenio and this family. There was also a Pablo de Jesus Galvan, who married Maria Asencion Lopez on 5 Feb 1758 in Pinos. He was also from Silao, and he was son of Bartolome Galvan and Juana Maria Sanchez. Again, there was no sign of any contact between Eugenio and this family.
Earlier this summer, I really started dredging the parish archives of Silao, looking through the baptisms, marriages and IMs. I found other persons surnamed Galvan, some who were the children of Bartolome Galvan cc Josefa de Chagoya, others who were children of Bartolome Galvan cc Juana Maria Sanchez aka Rivera. I was later able to determine that this Bartolome Galvan was the same person, and that he had married twice - first to Josefa Chagoya, around 1715, and then to Juana Maria Sanchez, around 1725. 
Throughout this, I could still find no record of a Eugenio Rufino Galvan marrying Maria Dolores Fernandez. But I DID find the IM of one Eugenio Rufino Juarez marrying a Maria Dolores Santoyo, dated 30 Oct 1761. He was the son of Bartolome Juarez and Ana Maria Sanchez, and she was hija de padres no conocidos. Could they possibly be my ancestors? Their first names coincided - and like I said, “Eugenio Rufino” is a rare enough name. And what a coincidence, that his parents were named BARTOLOME Juarez and Ana MARIA SANCHEZ: could they be the same BARTOLOME Galvan and Juana MARIA SANCHEZ? 
So I dug deeper and deeper. And finally, I found a record verifying that Bartolome Galvan and Bartolome Juarez were one and the same person: baptized on 7 Jul 1720 was Paula Josefa daughter of Bartolome Galvan and Josefa de Chagoya; when Paula Josefa married on 1 Aug 1735, she used the surname “Juarez” and she named her parents as Bartolome Juarez and Josefa de Chagoya! With this new information, I found more records, children of Bartolome Juarez and his two wives, finally hitting pay dirt with the baptism of Eugenio Rufino, hijo de Bartolome Juarez y de Juana Maria, 16 Sep 1742 - ¡GOL! ¡GOL! ¡GOL! ¡GOL! I even found the baptism records of the aforementioned Juan Joseph “Juarez” (b. 4 Feb 1762) and Maria Josefa “Juarez” (b 16 Jun 1764), both in Silao.

Just goes to show you: perseverance + patience + hard work = results!

The children of Bartolome Juarez aka Galvan (d. 14 Sep 1759, Silao Gto) cc Josefa de Chagoya (d. 6 Jun 1724, Silao Gto.

1. Juan Joseph Juarez, m. Marcela Quiteria Santos, 30 Jan 1729, Silao Gto.

2. Felipe de Santiago Galvan Chagoya m. Juana Francisca Xaviera Delgado, 14 Aug 1738, Santa Fe, Guanajuato.

3. Dorotea Gertrudis Juarez Chagoya, b. 20 Feb 1718, Silao Gto; im. Juan Nicolas de Castro y Garnica, 24 Sep 1734, Silao Gto; m2. Celedonio Victorino, 2 Mar 1756, Silao Gto.

4. Paula Josefa Galvan aka Juarez Chagoya, b. 7 Jul 1720, Silao Gto; m. Basilio Victoriano Valdes, 1 Aug 1735, Santa Fe, Guanajuato.

5. Maria Gertrudis de la Cruz Chagoya, b. 23 Sep 1722, Silao Gto. Note: on this record, the father is named as "Bartolome de la Cruz". Though I cant say with complete certainty that he is the same person, I can find no other record of a Josefa de Chagoya married to a Bartolome de la Cruz.  

The children of Bartolome Juarez aka Galvan cc Juana Maria Sanchez aka Rivera

1. Joseph Alberto Juarez Sanchez, b. 10 Apr 1726, Silao Gto; m. Maria Nicolasa de Avalos  
2. Maria Candida Susana Juarez Rivera, b. 25 Sep 1728, , Silao Gto.

3. Pablo de Jesus Galvan Sanchez, m. Maria Asencion Lopez, 5 Feb 1758, Pinos, Zac.

4. Joseph Gabriel Galvan Sanchez, b. 25 Mar 1734, Silao Gto.
5. Dario Tomas Juarez Sanchez, b. 7 Jan 1737, Silao Gto; m. Josefa Joaquina Fernandez, 3 Mar 1778, Silao Gto.

6. Luis Seferino Juarez Sanchez, b. 2 Sep 1739, Silao Gto.

7. Eugenio Rufino Juarez aka Galvan, b. 16 Sep 1742, Silao Gto; im1. Maria Dolores Santoyo aka Fernandez, 30 Oct 1761, Silao Gto; m2. Maria Micaela Cordoba, 10 Jun 1793, Catorce Slp.
8. Juana Apolonia Juarez Rivera, b. 23 Feb 1745, Silao Gto.


The children of Eugenio Rufino Juarez aka Galvan cc Maria Dolores Santoyo aka Fernandez

1.  Juan Joseph Galvan Fernandez, b. 4 Feb 1762, Silao Gto.

2. Maria Josefa Gervasia Galvan Fernandez, b. 1 Jul 1764, Silao Gto; m. Joaquin Gaitan Muñoz

3. Maria de los Reyes Galvan Hernandez, d. 22 Sep 1819, Catorce Slp; m. Francisco Casiano Villanueva Cepeda

4. José de la Luz Galvan Fernandez, m. Jacinta Camacho Salazar, 5 Mar 1807, Catorce Slp.

5. Maria Anna Josefa Mendez Fernandez, m. Antonio Abad del Castillo Aguayo, 26 Apr 1802, Catorce Slp.


I descend from Maria Josefa Galvan, who married Joaquin Gaitan, of Sierra de Pinos, around 1781.

Burial of Maria Dolores Fernandez
https://www.familysearch.org/ark:/61903/3:1:939N-BM35-B?i=688&wc=MC76-1…
IM de Eugenio Rufino Galvan y Maria Micaela Cordoba
https://www.familysearch.org/ark:/61903/3:1:33SQ-GGL6-DY?i=44&wc=3PHV-8…
IM de Eugenio Rufino Juarez y Maria de los Dolores Santoyo
https://www.familysearch.org/ark:/61903/3:1:33SQ-GG5R-479?i=371&wc=3VHJ…
Bautismo de Eugenio Rufino Juarez
https://www.familysearch.org/ark:/61903/3:1:33SQ-GG2F-KVW?i=124&wc=3VH8…

Saludos!
Manny Díez Hermosillo