> "45 unique signs, which were apparently made by pressing pre-formed hieroglyphic "seals""

Several problems exist with this...

1) Unique signs... If one had gone to the problem of carving seals to impress signs, one would expect examples to be far more common than ONE disc...

2) "Pressing Seals" Even the somewhat concurrent Hammurabi Code examples (1700BCE) are all hand cut. I am unaware of other examples of "stamped" hieroglyphics. In fact, most self respecting scribes would have a cow if their "art & craft" were reduced to hand stamps any fool could use. I am aware the Egyptians stamped hieroglyphics on bricks, and the Romans used stamps to identify amphora tags, but both these seemed to have occurred some 1,000-1,500 years in the future.

This strikes me as an approach someone familiar with the printing press & typeset might come up with.

Jammer