@thehiddenfaceof Since some pieces were found. Descriptions of the marble reliefs after the removal attempt show there were less and less, with one panel in the 18th century if I'm correct. So the reliefs didn't go missing all at once. There may be some around, it's a difficult puzzle to solve.
@thehiddenfaceof I also wonder who. Those marbles were very big and weighed a lot, and their position made it difficult to remove. So if they were removed, those who did it knew what they were doing. It's also possible the marbles fell and broke in the fall and the pieces were just picked up.
@thehiddenfaceof From what I read he nearly got the reliefs but then a mob stopped him, due to superstition that the statues offered some protection. What remained was either hacked or fell due to disrepair. Or did I read it wrong? I haven't reconstructed the small gate I still need to research.