Complex sentence: The manufacture of the statues would not have permitted them to last long, and since they were buried in pristine condition, it is possible that they were never on display for any extended period of time but rather produced for the purpose of intentional burial.
Split into simpler sentences: The manufacture of the statues would not have permitted them to last long. And since they were buried in pristine condition it is possible that they were never on display for any extended period of time, but rather produced for the purpose of intentional burial.