I've scanned selected pages from "Catálogo del Archivo del Registro Público de la Propiedad de Guadalajara: Libros de Hipotecas, 1566-1820," by David J. Robinson & Linda Greenow. Gobierno de Jalisco, Guadalajara, Mexico (1986).

A very small percentage (<2%)of persons were able to obtain a mortgage in New Spain, generally the wealthy and landed. For this reason, the catalog represents a very limited segment of our Mexican ancestors.

I believe the actual Libros de Hipotecas are located at the "Archivo Histórico de Jalisco."