Wahabite dagger ? or janbiyya?

[gp]

Originally Posted by Jim McDougall

... there is an illustration (I have not yet relocated) with him wearing one of these.

there are plural editions of the book describing this voyage and all have different pictures in them; some fotos and some drawings...
as for the description "Wahabite daggers" , I think that as nonsensical as their doesn't exists in a similar way catholic, orthodox, protestant, sunni or sjia weapons.
Whahabites was / is a movement named not by the Arabs but Western world after its founder (Muḥammad ibn ʿAbd al-Wahhāb ibn Sulaymān al-Tamīm) who came from the Najd and was member of the Banu Tamim tribe
But that doesn't answer which kind of dagger Sir Richard had...sorry that I am not able to assist any further....it al depends which tribal identity Sir Richard took/ copied...