You do not need to have hard evidence. You only need to know the names of your family, where they lived and their approximate birth year. With that information the Commission will have each of the member companies search their archives. If there is a match, they will pay the entire amount adjusted to current value of the policy. There is no limit.
Companies are happy there have been so few claims.
The money to pay for these claims comes out of the general funds of these companies so they are delighted there have been so few claims. Make a claim for your family. It is easy and free. Simply check the list below for the telephone number for your country. Most numbers are toll free.