We have been researching to break through the brick wall of a 1789 illegitimate birth in Hay, Breconshire. That is our direct surname origin (although the numerous Vaughans in the Middle Wye and Usk Valleys all claim descent from Sir Roger Vaughan of Bredwardine, legitimately or not - and we connect with a few other of those lines).
This weekend, I had some correspondence on Ancestry.com with another user who took some umbrage with us naming her direct ancestor as the putative father of John Vaughan (1789-1851). She gave me permission to share it with her Ancestry user name. Here is the correspondence: