San Judas Tadeo, Villanueva Zacatecas

Has anyone had any experience in researching records in The San Judas Tadeo church in Villanueva, Zacatecas? My wife and I are planning to visit there this summer. Her Corvera and Marquez ancestors lived there. I'm just curious as to how approachable the church staff would be for us to see their old written records. Thank you so much for any advice you can offer.