Archivo Histórico de Notarías

From the longer Spanish Wikipedia page

In Mexico City, the General Archive of Notaries of the Federal District (more commonly, the General Archive of Notaries ), dependent on the General Directorate for Legal and Legislative Studies, is an instance of the Government of Mexico City that is in charge of conservation, custody and reproduction of the documents contained in its appendices and protocols, as well as the keeping of the stamps of notaries public and other notarial documents deposited therein. It includes two collections: the Historical Collection, 3 located since 2005 in the Ex Corpus Christi Temple, in the Historic Center of Mexico City, and the Contemporary Archive, 4 in Candelaria de los Patos.

The website, in Spanish, is here.

Some information in Spanish, dating to 2012, can be found here.