This is the question of questions for all genealogists. When do you cease searching? When do you concede that the record either does not exist or is simply somewhere else?
I just completed an article on the family of Abraham Clark of Oyster River (Durham), N.H. Two of his daughters marry in Salem, Massachusetts and I had their marriage records from the published Salem Vital Records. Those records showed that the marriage came from the Friends' (i.e. Quakers) Records. So I went the extra step and drove to Rhode Island to see the actual records.
Why did I do that? The Salem VRs give the father of both bride and groom, but I was wondering if the mothers were also given, as they invariably are in the Friends' records in Dover, N.H. That wasn't there, but the witnesses for the marriages were listed. And in the Salem Friends' records, they list the witnesses in two groups: witnesses and relations. So, we know that one column of names were related to either the bride or groom. That was good to know. So this is where I can help a third party. Joseph Buxton married Esther (---) according to Walter Goodwin Davis's treatment of the family. In Torrey's, I see Joseph Buxton married Esther Southwick (?). I think that is a good possibility seeing that their three sons (and ostensibly first cousins of the groom) are listed on the marriage record of Samuel Osborne, Jr. and Mary Clark.