Just some observations regarding your Jezail, particularly the lock.
The upside down RRRs are not what one would expect to find on a "genuine" jezail. Also the cock is clearly hand made and very poorly IMHO. Your photos do not show the pan interior. The touch hole should line up perfectly with the bottom of the pan. If it does not, then it is likely that the barrel and lock have been mis matched. Does the lock function OK and create a spark?
Having said all that it is IMHO still worth keeping as an example of Afghani back street gunmaking.
There is another recent Post showing a similar gun
http://www.vikingsword.com/vb/showthread.php?t=30433
Stu