The protesting owner, for whom witnesses came forward - does not need a document to be witnessed, nor does the protestor need to require a document -- can be done on its own. And one can come back and claim coercion to testify, etc. There's no need for a signed document, but if you're going to have one, you need witnesses throughout the process. Also, this kind of kinyan should, perhaps be written down, for it to take effect. Plus, more notifications out of Nehardea. Also, when the document includes mention of a concealed gift -- why is it concealed? How should it be prepared? Or preemptively signing away property...?