Transcript: "The Inclosed letters from my father / when in the Tower to the Duke of Hamilton, as likewise the papers, here in the Custody of John Hood Esq. Governor of the Isle of Man, and delivered by him to me att Edinburgh the 31 May 1775."
He has signed it 'Erroll' as he dropped the disgraced title of 'Kilmarnock' and inherited his Grandfather's title 'Earl of Erroll' from his mother's side of the family.