Excellent call Iain! I think I must be getting too cautious in my old age
as I hesitated to be that optimistic, but looking at it, your astute eye has pretty well caught the key points. I think that with that being the case this could very well be an old Mamluk blade.
While many of these swords were taken by the Ottomans to Istanbul, there were certainly many which diffused into surrounding regions over time.
All the best,
Jim