Having recently gone through the process of sorting and distribution of the parents' belongings I strongly suggest that responsible collectors should, at a minimum, be sure to clearly identify each item of significant value with; description, source acquired from, amount paid and value at the time you are cataloguing them. That will at least give your family, or other estate administrator, notice that the items have special value and some idea of how much that amounts to. And some of that information will be relevant in valuing the estate for purposes of probate, if needed. Of course discussing this ahead of time with your prospective heirs would be appropriate, as would perhaps some further instructions as to best means of disposing of items family members are not interested in.