Avgas in Gabon
As far as i can remember and that was back in 2005....avgas was available from a small local company based in Port gentil FOOG...i m talking about SCD Aviation.(they were flying a 206 and a maule)
My only advise will be to be very carefull as the chief pilot,a belgian guy has absolutely no commun sens and will probably try to sell you very old fuel drums having stay on the ramp for ages! So ask for a receipt and i really mean to condition the deal on the receipt avaibility!
Happy contrails
PS: otherwise you could also try Air Affaire Gabon in FOOL and Malabo but much more expensive