Research in Sombrerete and Fresnillo

I am posting on this forum as my inquiry is more general than specific.
I have been sporadically viewing LDS film # 0654983 - "Registro Parroquiales - San Juan Bautiista, Sombrerete, Zacatecas: Matrimonios, 1793-1854". My original search was to find marriage information for Julio Duenas (~ over the n) and Maria Guadalupe Duran. The record shows that they were married on 29 May 1853. Julio (b. about 1831) was the son of Victor Duenas and Manuela Gutierrez. Ma. Guadalupe was the daughter of Don Luis Duran and Dona (~ over the n) Lorenza Rodriguiz.

Does anyone have experience researching in the area of Sombrerete? How about Fresnillo (for which there seems to be very few films)?

Thanks for any info you might be able to share.

Natalie Castro Coleman
Researching the following surnames: Castro, Duenas, Garcia