Thomas Wynn is unknown, but it may have been Thomas Wynn (1736-1807) the son of Sir John Wynn, 2nd Baronet, of Glynllifon, Caernarvonshire. He succeeded his father as 3rd Baronet in 1773, and was created Baron Newborough in 1776. He served as Auditor of land revenue in Wales in 1756-81; Lord Lieutenant of Caernarvonshire in 1761-81; constable of Caernarvon Castle in 1761-81; Clerk of the Crown for North Wales in 1793-1807; and he was MP for Caernarvonshire in 1761-74, St Ives in 1775-80 and Beaumaris in 1796-1807.

The intended location for this cupola design is not known. Moreover, the drawing is undated, but if it was designed for the Thomas Wynn who became 3rd Baronet and then Lord Newborough, it would predate 1773 when he inherited from his father and became Sir Thomas rather than ‘Thos Wynn Esq’. The design is not known to have been executed.

Literature:
Wynn, Thomas, 1st Baron Newborough [I] (1736-1807), of Glynllifon, Caern.’, History of Parliament online

Frances Sands, 2015