This might help you in your search. The 1910 puerto rico census is online and digitized. I know of only one Javier in my family. You are correct they are from the Aguada, Aguadilla area. My g-g grandmother was Ferreris Javier de Lopez, Manuela. I have no furher information about her.
The website is located at http://www.rootsweb.com/~prsanjua/c001709.htm
You might check some of the other barrios, but in Espinal there are several other families listed under Javier