Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 146,757 pages of information and 232,400 images on early companies, their products and the people who designed and built them.
of North Valley Tool Works, Keighley
1873 Partnership dissolved: 'Joseph Dean, John Spencer, James Smith, and John Grace, as Dean, Spencer and Co., machine tool makers, North Valley Tool Works, Keighley ; John Spencer retiring from 6th January last.' 
Relationship with Dean, Smith and Grace?