I was not sure of the Clapsaddle connection you mention - you say "his" g-g-grandfather was Jacob Sharp - did you mean your husband's or did you mean the Clapsaddle person? I am asking so I know if the Clapsaddle connection was far back or more recent (1800's-1900's)??
Could it be that one of the sisters of Peter, or on of his daughters married a Clapsaddle ? I don't want to look for these marriages if you already know them and have eliminated that connection.