Richard Burton’s brief comment (Burton 1876, pg 208), from a journey in 1862, was: “The ‘terrible war-axe’ is the usual poor little tomahawk, more like a toy than a tool.” This was at the village of Mayyan (Magyan according to Tessmann 1913) on the Mbokwe (now Mbeya) River. I'm guessing that Mayan/Magyan is the present day Mayangone, which is in approximately the right place.

Illustrations by Fernand Grébert suggest that some of these Fang axes could be much more substantial, e.g. folio 274, 258, 221, 93.

Afrique Equatoriale Francis. Ogooue. de 1913-1917 a 1932.

Some very large examples reside in Musée d'ethnographie de Neuchâtel.