Edward Duffield was a Philadelphia craftsman, a maker of watch and clock works, though not their wooden cases. Duffield is cited in various sources as born 1720 or 1741, and he died 1801. (Perhaps there is confusion caused by his having a son of the same name.) The online Encyclopedia of Antiques - Biography
writes that Duffield's clocks "were distinguished for good workmanship and good timekeeping." Duffield is credited with having created the dies for pewter medals given to officers of the British (colonial) army who fought in the Battle of Kittaning, near Pittsburgh, during the French and Indian Wars in 1756. The medals are cited as being the first ones "made from American dies and struck in what is now the United States."
Duffield was one of two wardens elected for the city of Philadelphia in 1769; he was also a vestryman of Christ Church.
Franklin owned at least 2 clocks made by Duffield, who was an associate and trusted friend. Franklin designated him as an executor of his will (with John Jay, Francis Hopkinson, and Henry Hill.