Sorry. You can't convince me that the recipient of a letter who insists on using a nom de plume [but they supposedly found who it was anyway] had an undated, unsigned letter that specified it not be published [moral turpitude, anyone?] can constitute any kind of evidence.
Besides...did you ever see a Madison correspondence that DID NOT have both a date and a signature?
So you blame sloppy work on the part of Hunt when he edited Madison's writings into a 9 volume collection? Are you suggesting none of the letters in the collection are Madison's? Or just the ones that disagree with you?