Hi blue lander,
Here you can also find some styles of pommels:
http://www.vikingsword.com/vb/showthread.php?t=16478, and there are another interesting threads.
Re. a.m. link, your sheath and blade is similar to the dagger, which allegedly came from Agadez area (but I think it could be commonly used in central part of the territoty - maybe Niger, south Algeria, western third of Libya ?).
I have strange feeling, that, besides the classical "old styles" handles and pommels, the "art of hanndles" of Tuareg daggers is alive even currently and the fashioners are relatively creative
(Ibrahiim, the X shaped handle is not Tuareg, but Hadendoa, Habab)
Regards,
Martin