Wills are not public documents unless it serves a public interest. When Executors apply to the Court for a Grant of Probate, Court circulars would mention the Will and, it is through the circular that one would come to know that a Will exists. If the testamentary dispositions create a Trust within a Will then it rests upon the Executors to locate and inform the Trustees. If the Trustees cannot be located, then a Deed of Variation to the Will can be applied for in Court by the Executors. Unless, of course, the Executors are also the Trustees.

If someone knows a Will exists but, even with best effort, could not locate it, a Letter of Administration in Probate could be applied for (subject to other legal rules) as though there was no Will and the Court would likely treat the deceased as to have died intestate.

As I do not have the specifics, this is just rough overview of the general rule on Wills and Probate which apply to your queries, Lynn. Hope it helps.