It's by Noly Panaligan!
I've finally confirmed the artist of the cover to Tagalog Klasiks #109 featured in the March 16 entry below. Noly Panaligan's son Hero sent an email to confirm that the painting was done by his father, who was the writer and artist of Payaso currently being serialized on the pages of Tagalog Klasiks at the time.
Hero recalls seeing studies of the above painting in his grandmother's house in Malibay.
