Originally Posted by mariusgmioc
Judging from the photos the two shibriyas appear to be of the very same or at least very similar workmanship.
The fact that the one in the original posting is not signed, might be because it was made by an apprentice, or was made at an earlier stage when the maker did not sign his works.
From the information I collected he did not have an apprentice. Sadly the craft in this family died out with this generation. Their descendants that I know personally have lost interest in it.
Now while all the pieces I saw made by Ali are signed, does not mean that its a must. Same case for his brother named Sulaiman who worked in Riyadh, I own 4 pieces made by him. One is signed the rest aren't. He did not have an apprentice either.