scholars
Do not be afraid to send cold emails and Facebook message requests to strangers. I have done this myself. I reached out to all sorts of people ranging from scholars (whose research intersected with the life of my great-great-grandparent) to distant relatives (who might remember names that my parents and grandparents cannot). I followed Facebook pages like Historic San Mateo and joined Facebook groups like Manila Nostalgia where people share old photos and stories. Maybe you can even talk to the oldest living person in your barangay?