Without each of these documents, you won't be in a position to enter Gabon, so ensure you get your visa for Gabon in place well before your trip. It isn't prescribed you do likewise. Fortunately, it wasn't crucial.
You should also think about checking with your transport provider or travel company to ensure your passport and other travel documents fulfill their requirements. The tedious portion of travelling for Philippine passport holders is whenever the destination country demands a visa. When it has to do with traveling overseas, the host country often needs a visa, particularly if you're planning to stay for a protracted amount of time.