David, That is one source of SEYS. There are several others. There are several spellings, and origins. SEIJS, SEAS, SAIS, SAYES, SEYTZ, SYTZ, ZEYTS, SEITZ,SEISS, SAYS, SAYERS, etc. 1. A small bird known as Sijs. 2. A Welsh word meaning Englishman Sais, which developedinto SEYS 3. Of Norman origin, first appeared in ancient midieval records in Shropshire, Eng. 4.Came with Duke of Alva ae Sayes to Belgium during occupation of Spain. 5. Sisk, a vaiation, derived from SECKETH, meaning 6th child in Welsh. 6. Derived from the Gaelic name, MacSithigh, meaning a descendent of SITHIGH. They came to Ireland as gallowglas warriors from the Western Isles of Scotland (The Hebrides) in the 13th century. The name was Anglified to MacSheehy (Sheahy), then to Shaw, Sey, Seay, Mac Shea, Mac Shee, ans Sawey. There are at least 3 SEYS coats of armor.
I would like very much to know where you were born, and if your Mother's name is Lois.