I'm going the long way round but sometimes it works.
Will of James Jacob (no S) 1720 listed as Jacobi Jacob on ancestry of Mertin (sp) Surrey
Bequests to John Dan Cammell? and his children Charles, William, Hannah and Katherine.
His late wife's sister Alice Conyers and her son Edward.
The bulk of his estate goes to his dear brother Benjamin Jacob senior of Mertin Surrey
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So they are probably sons of John Jacobs died 1678 of Merton Surrey who has children Margaret wife of John Fo?, Catherine, James, Thomas and Benjamin.