Interesting piece you got there.
These strong rifled barrels can also be seen in Sind guns.
http://www.vikingsword.com/vb/showth...?t=3636&page=1
Looks like the rich markings are indeed imitating the European methods. Aren't the shield with the Arabic script and the square inset with the horse in inverted positions ?
Experts like Ward may come around with better coments.
fernando