Sorry, I only know a couple of Gresham from 1764 and earlier, nothing later. In fact these are the ones I know:
1764: Robert Grissom of County and Parish of Amherst bound himself to Thomas Merritt of the parish aforesaid to be taught in the Trade an Occupation of Carpenter for five years.
Robert (half Monacan) would have been Thomas Merritt's second cousin. Robert's father was Thomas Gresham of Essex Co Va. Thomas Gresham son of Robert and Frances (Merritt) Gresham of Essex.