As i mentioned elsewhere that you posted this i am of the opinion that Tridacna (giant clam shell) was considered a rare and valuable material all on it's own. If it was considered the "poor man's ivory" i would think we would see it more often. I have seen far more bone pommels, which is what i would call "poor man's ivory" used on kris than Tridacna. I would consider this a rare and valuable find.
