Well, then it could be just about anything... Regarding Ottoman Trophy of Arms, I found this in Wiki ”Every sultan of the Ottoman Empire had his own monogram, called the tughra, which served as a royal symbol. A coat of arms in the European heraldic sense was created in the late 19th century. Hampton Court requested from the Ottoman Empire the coat of arms to be included in their collection. As the coat of arms had not been previously used in the Ottoman Empire, it was designed after this request, and the final design was adopted by Sultan Abdul Hamid II on 17 April 1882.” See picture attached. Something like this could be engraved on the hilt. The engraving at the top of the trophy of arms on the hilt could just be a tughra?