Dave, you are right about sham - it generally "runs the length of the blade". But it is also characterized by low contrast and low activity! The pattern on your blade is quite bold and active, and certainly of quite good quality. I'd not call it anywhere close to the "lowest on the list of desirable wootz patterns"
It's a nice blade! I also agree with A.alnakkas that the cross and coftgari inscription are recent (meaning post 19th Century
) and likely of Syrian origin, as could be the blade itself. I agree the blade is at least 19th Century.