Kenworthys were, according to their own publicity, established in 1880. The Kenworthy family began as grocers in Stalybridge in the mid-19th century, before James Kenworthy (1867-1921) established a business as a jeweller and pawnbroker in 1901 at Stamford Street, Stalybridge, later moving to Ashton-under-Lyne in 1904. The business became a limited company (Kenart Limited) by the late 1920s, run by Thomas (1895-1955) and Frederick (b.1900) Kenworthy, the sons of James; they expanded the business, opening branches in Birmingham's Jewellery Quarter. Thomas was elected mayor of Stalybridge in 1947, but died in 1955. The business was continued by his daughter, Margaret, who later, in 1961, married Christopher Collins. The company was closed in 2003.
Information on the Kenworthy family history and business kindly shared by Jill Morris, at Tameside Local Studies & Archives - see tamesop for Jill's blog on the Kenworthy's.