As already pointed out, the blade really does have all the hallmarks of a Katana. Is it possible that it is a re-mounted katana? Shipping routes from Japan to Europe via the Suez Canal (open to shipping in 1869) were, I believe, common. Before the opening of the canal, goods were sometimes transported by being offloaded from ships and carried overland between the Mediterranean and the Red Sea. This was often quicker and safer (the cape was often treacherous to sea farers.)
It is not impossible for a Japanese sword or blade to find its way to the middle east.......and then re-mounted.
A very interesting sword........if only your saif could talk.....
