Hi Lew,  
I've attached a couple additional photos below of the scabbard... the wear and patina IMHO seemed to indicate a bit more age.  Tirri shows five "Wahabite" jambiyas, of which three look nearly identical to mine, all identified as "late 19th/early 20th."  Bad information?  What stylistic differences would mark an older piece?  Also, I was under the impression the ridged blades (no ground fullers leaving a ridge vis stock removal, but a forged ridge) were good indicators of age? 
 
 
 
