help to identify newly aquired old yataghan

[mavi1970]

hi, thanks for all your help in previous posts, but this is a new old yataghan i have aquired recently. its about 28 inches in length, with a circle etched in the middle of the blade with almost a davids cross, this design continues on the leather covered scabbard. the designs are similair but not exactly the same. there is also other designs etched into the other side but of corrosion right over them it is hard to read or make out the arabic script but it is really beautifull. there is a peice of the brass/silver cover on the area where the hilt attaches to the blade, and under it is a dark almost tar like or rock hard mollasses type substance. the handle is of horn or some sort of bone, which has a worm hole in it on one edge. this sword is in need of repair but, i think i will leave it as such, any help in identifying this sword, and age would be appreciated.