quite lucky with your nimcha. In my opinion it is a XVII-XVIII century sword. Very nice blade, fascinating and in almost perfect conditions. The andle is most probably horn although it is partly damaged it is still very nice. The maker marks is typical of that period. There is an incredible collection of similar Nimcha in display at the Museum of La valletta, in Malta, that I invite everybody to visit. They say that the swrods were collected after the famous battle of the 1565 won from the Malta knights (the former knights of S.John of Jerusalem) that in the previous centuries had their capital in Rodi (
http://hubpages.com/hub/Battle-of-Malta-1565-AD). Apparently the siege was carried out by Suleiman and therefore one could expect to find other kind of sword, more linked to the Ottomans. However, a large part of the arm was supported by the muslim commandant Dragut. In the article I addressed they say he was the King of Tripoli but at the Museum is written that his headquarter was the island of Djerba. I bought a quite similar sword some years ago and I enclose its photo. The blade of my Nimcha has some damages but still the same form. In Malta there is a large variety of blades, possibly from 40 to 80 cm long. They are thinner near the base of the blade and enlarge toward the tip in an asymmetrical way exactly as your and my sword. Another splendid Nimcha has been sold this year at the auction of the Hermann-Historica (Auction 58, n.200) that is also referred to the XVII century. As you can see the guard of my Nimcha is different. It has a nicely decorated bridge at the guard. In Malta most of the sword has a handle similar to your sword and only few of my type. I suppose it is connected to a different geographic provenience but I am not sure which is.
Enjoy your sword and best compliments
Mauro