from where this sword

[Iain]

I can't say for sure, hopefully someone else will be able to say more, but the pattern of decoration for sure looks like Berber work - as you rightly noted their is a similarity with flyssa decorative patterns.

Berbers also use cowry shells for decoration.

I would say it's not a particularly old piece, but that's just opinion really based on the style.

[EDIT] I see Teodor beat me to it!