As mentioned to Sarah in my previous posting, since my original post on 9/4/2002, my uncle Preciliano passed away.
Is it possible that you can ask your aunts/uncles if they remember anything about their mother Julia Aguilar? The year of birth that you provided for Julia seems about right if she was 18 when she gave birth to Preciliano
As far as I know, my uncle Preciliano was the first child born to Julia Aguilar in June of 1912. If you could find out whether some of your aunts/uncles were born before 1912 that would be a big help in trying to find out if this is the right Julia. As mentioned to Sarah in the previous post, the whole story behind Julia's disappearance is odd.
If it wouldn't be any trouble, is there a way that I could look at the photo you have of Julia and your father?