I join a drawing with the full legend of this coin.
Even if this coin is known since a long time, the full legend including the word 'ad'l has been noticed only recently (1990 or 91, I think), due to the fact that the lower parts of the legend are very often cut (as on yours..) / = Valentine n°664.
You can see on your dam the vertical leg of the "lam" of 'ad'l (which cut in fact the "S" of falus and the "B" of zarb) and the very small end of the "A" of 'ad'l in the "wav" of falus.
The reverse should possess the legend "fi tarikh nuhsad..."