An advertisement that give a clue to the last working date of James Manners Junior:

Phene & Jones - London - 1763
The earlier address shown, the corner of Northumberland Court, facing St Martin's Lane, Charing Cross is not noted in Grimwade. The later address, Villiers Street, York Buildings, was his father's, James Manners (p.590), premises since c.1745.
Source of advertisement: Gazetteer and London Advertiser - Thursday 30th June 1763.
Trev.