I've thought about this as well and my answer, thus far, has been to appoint someone to act as an consignment agent --- who is knowledgeable about the collection --- to determine the best way at that time to dispose of the collection. Today it might be Ebay for some, CCGTCC auction for the higher-end ones, etc. In the future, who knows.

Then the proceeds are divided as I saw fit (with a consignment commission percentage to the seller). I would probably amend that with a codocil giving rights to (specific) members of my family would would want to carry on the collection.