The hilt style (with the relatively thin brass guard and the straight grip with relatively straight projecting relatively symmetric finger hook, and the small projection along the back of the pommel) and in particular the scabbard suggest an Algerian origin. The scabbard is very reminiscent of those on Algerian flyssa. See
here for other examples of such scabbards on flyssa and nimcha.
For comparison here are various styles of nimcha grips, where yours is (to my eyes) closest to the third from the left in overall shape:
The Zanzibar types on the right of it are more curved and have a bigger finger hook, while the Moroccan ones on the left are also slightly more curved and usually have a steel guard with thicker branches, a thicker cross piece, and no projection along the back.
Personally I would leave the grip as is. I certainly wouldn't replace it. This style is pretty rare so even a damaged grip is interesting.