Egyptians are like goblins: the fact that many of their items have been sold does not dissuade them from thinking that they still own them.
If it disappeared in the “1980s” I bet there were laws forbidding sales. We have same laws in places regarding Native American artifacts.
I bet blam knows.
I don't think the French selling stolen goods to the British really counts against the Egyptians. There are plenty of arguments that can be made for who has rights to what based on cultural changes and religion, but you have to admit that Egypt has one of the richest and most pillaged archeological histories in the world. Don't they have a right to their history?