The flag is assigned to the 1851 sailing; the painted source is labelled 1840–1850.
Tyleston is described as operating from Nantucket from 1839, although agency entries begin in 1838. Later owners included Freeman Lowell, ? L. Adams, probably Zenas, and Edward W. Gardner. Agents included David Thane, A.W. Starbuck, Zenas L. Adams and Edward W. Gardner. She was condemned in 1854.
Keep the explicit scope label independent; no alias or company identity is inferred.