Hi Chris,
I think that the author of your diary is Thomas Weston of Tenterden (1746-1819). In 1793 he had the following living siblings: Elizabeth (1748-1797), Stringer (1750-1803), Mary (1751-1829), Sarah (1753-1824), Jane (1756-1817), William (1758-1815), George (1761-1801) and Richard (1763-1764); and children Elizabeth Hyland (1771-1846), Harriot (1773-1855), Jane (1776-1863), Thomas (1780-1827), and John Tempest (1784-1848) (my ancestor).
Thomas's widowed mother Elizabeth had lived at Old Wilsley outside Cranbrook until her death in 1788, but Thomas's main property seems to have been Cheyne Court near Ivychurch in Romney Marsh and he was a member of the town corporation of Tenterden. There is a wall plaque about him in St. Mildred's church there.
As a descendant, I would be very interested in seeing a copy of his diary.
Regards,
Ian Christopher Weston.