I just found "Minutes for a Genealogy of George Jacobs, Senior, of Salem Village..." in the Historical Collections of the Essex Institute, Vol I, p. 52-55 by C.M. Endicott. This provides some genealogical info to the 5th generation.
However, you will want to work back in time to this information and depending upon how strict your documentation requirements are, you may want to find other independent authorities to validate/corroborate the research of Endicott.
However, you may find that your Jacobs line does not lead to George at all, there are other Jacobs in New England at this time.