If you are claiming to be a Gresham descendant with a U-198 haplog I have a big disappointment for you. You are not. It will be a shock. But Greshams in the East Anglia Project at FTDNA, the Big Y Gresham Surname Project, and the 111 marker test at FTDNA do not show this haplog.
Please disconnect yourself from any Gresham profiles so this haplog is no automatically assigned to other Greshams.
Mary Gresham