Thank you very much once again, Vera. I searched the entire alphabetical registry in Schopfloch (taufen, trauungen, bestattungen) and found not one single Bühl listed. However there is a Johann Adam Bühl who died in Grimmschwinden:
birth:
http://www.archion.de/p/dad7e84847/ - entry 13
death:
http://www.archion.de/p/8ac7c2f650/ - entry 17
(I am not sure if age at death is 73 or 77?)
I'm not even sure if these two records match the same man. Is it possible that Waldhäuslein was just a temporary residence? I was unable to locate a marriage record for Johann Adam Bühl and Maria Margaretha in Oberampfrach, Unterampfrach, or Schopfloch.