OROZCO (Orosco) family 1890s Tototlan, Jalisco

QUERY - OROZCO

OROZCO is one of my "brick wall" lines. I've posted an overview of this individual in my folder here: http://www.nuestrosranchos.com/en/CindyF

Here are the details for this line:
My 2nd gr-grandmother Maria Dolores Orozco was born in Tototlan, Jalisco in August 1895, probably the third child of Rafael Orozco (Orosco) and Manuela Vargas (Bargas). She came to the USA in November 1926 with her children to join her husband Jose Jimenez Jimenez who was already in Los Angeles, CA.

Their family group looks something like this (probable family members but not 100% sure on any of this):

PARENTS
Rafael Orozco, b. abt. 1868 in probably Jalisco
m. Manuela Vargas, b. abt. 1868 in probably Jalisco
Married in abt 1888 probably Jalisco

CHILDREN:
1. Piedela Orozco, f, b. abt. 1890 in Mexico
2. Maria de Jesus Orozco, f, b. abt. 1891 in possibly Tototlan, Jalisco, Mexico
3. Maria Dolores Orozco, f, b. 9 Aug 1895 in Tototlan, Jalisco, Mexico
4. Manuel Orozco, m, b. poss bet 1897-1910 in Mexico
5. Salvador Orozco, m, b. abt. 1912 in possiby Tototlan, Jalisco, Mexico
6. possibly Delfina Orozco, f

All names come from interviews with my grandmother and grandaunt before they passed away. Family oral tradition also states that Salvador was a guitar maker. He may also have been part of a symphony orchestra. One of the sons may have settled in the Chicago area of Illinois.

I have a couple of photos of her at different ages. I have one photo of Salvador who was considerably younger than she was (he was about the same age as her eldest daughter).

I have been unable to find vital records for this family, other than Maria Dolores' death certificate, issued in California. However, I'm in possession of a copy of an immigration document she brought with her from Mexico, "servicio de migracion", that gives her birthdate and place. I've been unable to locate church baptismal/marriage records at FamilySearch. Critical years are simply missing from the available films, much to my frustration. (BTW, does anyone have idea why some years are missing? Might they just not be online, but still available elsewhere?)

I'd appreciate leads or information from anyone who might know more about any of these individuals. Also, I'm going to be in Salt Lake City in November and will have a few precious hours to visit the family history library. So, I'm also looking for suggestions of what sorts of things to search out while I'm there.

Thanks!

CindyF