Hi Lew,
There was an extensive post about these recently I think. They are a "utility" knife which go behind the Khanjar of Oman, and probably behind the Jambiya of western arabia, but I have not seen one on a western scabbard.
Pic attached of an Omani Khanjar I have with Shafra.
Stu
Here is the thread I was thinking about.
http://www.vikingsword.com/vb/showth...ted+file+knife