your very welcome and I don't know who Moses's siblings were but baptism records may tell you if you find that book. I haven't checked but sometimes Surnames have a gen society of their own. There may be one on the Gilberts.
There is a Y-DNA project on the Gilberts. Our male line hasn't tested. I had contacted this group years ago.
http://www.janegilbert.org/gilbertdna/resultstable.htm