Forensic Document Examiner

I have several signatures made by my ancestor during the period of 1640-1680 in America. I now have a signature made in England in 1634 that appears to be a close match. In searching the Internet for a genealogical handwriting expert, I find all sorts of graphologists, but no forensic examiners. As I understand it, graphology is pseudo-science which determines the personality the writer. Whereas a forensic examiner compares the characteristics of two or more signatures to determine if they were made by the same person. The only forensic examiners I have found on the Internet are focused as expert witnesses for court cases with prohibitive fee schedules.

This must be a common requirement in genealogical research. I would appreciate hearing of the experience of others in similar efforts and, of course, any recommendations will be appreciated.