There are many people who research MOCKs in North Carolina. Look at http://mock.rootsweb.com
and if you desire subscribe to the MOCK-GEN-L list and you'll likely get responses.
In the meantime, check out http://freepages.genealogy.rootsweb.com/~mock/19a.html
On this working chart of Barbara Dittig's, I think you'll find that your Lucy is likely to be the wife of John MOCK with her maiden name reported to be FISHER. This is entry 126.96.36.199 on this chart. There is no son Willliam F listed but there is a son Philip born 1857 which coincides with other information you provided. These charts are incomplete so this seems to be a good starting point for you.
As you'll see, these charts go back several generations. I do not research the North Carolina MOCKs but I have looked into the claim that Johannes of Reading, Pennsylvania is the progenitor of these North Carolina MOCKs and the evidence is circumstantial and there are facts that point against this claim.
I have not personally researched any of the later generations but my understanding is that the North Carolina MOCK information is well documented. Hopefully your branch will insert into this tree.
Karen in Pennsylvania