I think upon further reflection, and further research prompted by excellent points made in Posts above, my thanks to TD and others, that what I now refer to as "The Letter" LOL, has to be relied upon only as a Threat, one that in actual fact you would be ill advised to carry out by actually going to Court, at least here in the U.K.
Of course, you must assert to any Legal person signing or Witnessing it, whatever, that the threat is real, see Post above, or they will not agree to notarise it or sign it. As in reality you will not use it in Court, you could get it Witnessed by two people, not related to you, and it would still look good, and not cost you.
The Defamation of Character thing would depend for success on a Court interpreting that damage to your reputation is more important than the Defence of Truth, which I doubt.
I can see a problem too under the Human Rights Act 1998 for U.K Residents, this is a very arcane point, but one you may have to fight to establish in Court, and again, the Court may not see things your way. I will not spell it out here, as the JW Legal Attack Dogs may not have spotted it.
Again I stress, The Letter may deter Elders, for fear they will personally be Sued, but to actually go to Court , and lose, would do none of us any favours, and cost a huge amount.