In the old cage, was the lid made of some kind of pig iron?

no.

The cages are made of willow wood, bamboo chips, rattan threads and other raw materials. The cage lids are covered with reed mats, bamboo sticks are used as nails, and rattan is used as ropes to sew them together. Therefore, the previous cages and lids were not made of cast iron.

Luggage is an ancient traditional handicraft, which is a type of cooking utensil. It is made of bamboo, wood, etc. and is mainly used for steaming food.