Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 146,984 pages of information and 232,838 images on early companies, their products and the people who designed and built them.
R. Blacklock and Co of 3 Holmeside, Sunderland, County Durham. Telephone: Sunderland 249. Cables: "Holmeside." (1929); of Black Hylton Road, Sunderland. Telephone: Sunderland 3149. (1947)
1929 Listed Exhibitor - British Industries Fair. Manufacturers of Wristlet Watch Straps of every description. Patentees of the "ODO" and "Tab" Straps. Immediate attachment. No sewing on required. Straps made for every market. (Stand No. O.20) 
1947 Listed Exhibitor - British Industries Fair. Manufacturers of Leather Wrist Straps of all types, with Various Fittings, Hooks, Joints, Ring-on, including "Eta" Cordettes, "Tab" and "Don" Wrist Straps, Leather Alberts, Moire Bands, Wholesale and Shipping only. (Olympia, Ground Floor, Stand No. E.1766)