My family is also from Ciales and they also lived in Vega Baja... According to my father 'Nicolas Caban Rios' he was born in Barcelona, Spain in December 1920, and his parents moved to Puerto Rico during the 1930's. They migrated from San Juan to Ciales and then to Vega Baja where I was born in 1956. My mother is Taino Indian and her descendents are from the original Boriqua from the Ciales area, her name is Herminia Hernandez and she was born in 1926...
My family now lives in Florida, P.R. and Vega Baja, I also searched the Galicia records in Spain, I will try the Records in Seville for the Rios lineage, but I think the Rios surname may have changed from 'de Los Rios' to just 'Rios' somewhere during the migration from Spain to Puerto Rico during the 1920-1930's immigrtion rush.
The only way is to get the original birth certificate from Spain for my father... from there then I can trace his parents and find what town or province in Spain his family belongs to.
You can contact me at nicolas.Rios@boeing.com or firstname.lastname@example.org