French Colonies. (Congo Francaise). 1910. Unstamped envelope endorsed 'l'agent Postal' and signed by the postmaster addressed to M'Ongouma, French Congo cancelled by 'Moyen Congo/ Oueso' double ring '31st Jan 10' with 'T' hand-stamp and bearing Congo Francaise Yvert 37, 50c violet and grey and Yvert 42, 10c rose tied by 'Congo Francaise/ Mongouma' and hand-stamped triangular 'T' for postage due. Superb item the Congo region was changed to French Equatorial Africa (A.E.F.) on Jan 15th 1910.
Very rare usage as Provisional Postage Due.
A similar cover in the "Dr Ed Grabowski' Spink, Africa sale November 13 2019 lot 585 sold for 1500 GBP. described as being 'fine and possibly unique'.