Salaams All, Khanjar Scabbard core construction is wood. It is perhaps not a Royal Khanjar because it carries the wrong sort of dagger(assuming it is original)... however, It could be a seven ringer Muscat Khanjar... It may be remembered that they also have 7 rings like the Royal Khanjar and it was technically only the hilt that Sheherezad designed after an Indian style of decoration to please her husband, the Sultan..The Muscat Khanjar has a formal tee shaped dagger. I appear to be seeing some sort of horn but if its wood then... its wood.
See
http://www.vikingsword.com/vb/showthread.php?t=14878 #143 for the Muscat style and the wood core at #5 of the same thread...
The other dagger with a lot of leather below the belt is of the Interior of Oman and is also the UAE style, though, also seen with chevron rings.
Regards,
Ibrahiim al Balooshi.