Hi Ed: I have collected several similar and sometimes different and conflicting papers. I am sure you know, that even geneologists admit, the Alexander family is sometimes very confusing. Maybe this will help you:
Virginia Heraldica
The City of Alexandria Va. Office of Historic Alexandria
William and Mary College Quarterly
I made a typo with the qoutation marks,please ignore. I
attempted to piece together what I have gathered to give
you a starting point.