Brick Wall on Mariano Penetrante b. ~1914, d. 1957

Question

Hello. Mariano Penetrante (1914-6 May 1957) is my great-grandfather, and I have been at a brick wall for the past few weeks trying to search for his parents. He died in Aparri, Cagayan, Philippines. My grandfather does not remember his father's [Mariano's] parents because he had never met them before. He was married to Juanita Reyes Gumarang. Please help!