Gabon: Transgabon airmail labels

Here is a rare and interesting airmail label issued by Transgabon airlines (Transports aérien du Gabon).
Mail with this label was carried by Transgabon from remote places without post offices to the capital Libreville and then posted by the company.

Year: 1959, Gummed. Günter Mair's catalogue no: - GAB-B-1a, perforated 11 ½ , sheets of 4(2x2),
also come on imperforated sheets,note metioned in catalog. As mine label is imperforated. black/grey-green
5*****