I worked in contract manufacturing years ago (metal stamping) and typically the contracting company pays for and owns the tooling. That way if the contract is up or the manufacturer folds, the tooling returns to the owner. It also makes the manufacturer have less leverage over price as the part can just be made elsewhere. I'm not sure if this process is the same in China but I have a hard time believing Shimano would allow a factory to own the dies and tooling to make Shimano parts and then keep them when the contract finishes.