Pease have a look at this set:
The Jambiya dagger in this set is most surely Arab, so will be the Shafra. (For a similar set see also Tirri p 95, Fig 56).
Years ago I had a long discussion with John Powell regarding the origin of this knife. He had a similar knife in his collection and supported the Nepali origin. Unfortunately we never agreed. Yet, after all I do believe in the Arab origin