Hi Aurangzeb,
Nice Christmas present!!!!
While I think this koummya appears of 20th century, and may well be toward the first half, it is a handsome dagger and good representative example. The koummya is typically considered the Moroccan variant of various daggers, especially the janbiyya (note the bulb on the tip of the sheath, known as the thum if I recall,and the curvature as seen on Arabian examples).
While these are most often associated with the Moroccan littoral, they were certainly used throughout most of the Maghreb. While away from my references at the moment, there is good material on these via search.
I think one of the most interesting features on these is the pommel, and there have been yet unsubstantiated suggestions that the shape is associated with the Italian cinqueda, which of course would have come to the North Africa littoral via Venetian traders.
Like most edged weapons in these regions, these are still important elements of tribal costume, and remain quite servicable, as you have noted in your desciption of this piece. While these are typically considered weapons from littoral regions, they of course may have diffused into the Sahara via tribal interaction and trade, but most likely in Morroccan areas.
All the best,
Jim