From Graces Guide
of 244 High Holborn, London, WC1. Telephone: Holborn 1427. (1929)
Ditto Address. Telephone: Holborn 1427-4004. Cables: "Optivorum, Westcent, London". (1947)
1765 Company established.
1929 Advert in British Industries Fair Catalogue as an Optical, Scientific and Photographic Exhibit. Manufacturers of Microscopes and Accessories, Astronomical Instruments, Lenses and Prisms (not photographic), Optical Benches and Accessories, Laboratory Instruments and Equipment, Scientific Models, Surveying Instruments, Aeronautical Instruments, Industrial Testing Apparatus. (Scientific Section - Stand No. O.14) 
1937 Scientific instrument manufacturers. 
1947 Listed Exhibitor - British Industries Fair. Manufacturer of Microscopes and allied Apparatus for Research, Medical, Education and Industry, Photo-Micro, Micro-Projection, and Illuminating Apparatus. Diascopes, Epidiascopes, Cathetometers, Measuring Instruments and Laboratory Equipment. Lenses, Prisms and Mirrors. 
1963 Vickers acquired the C. Baker Ltd microscope factory and new company called Vickers Instruments was formed. This continued as a profitable business for many years, mainly selling microscopes, surveying instruments and micro measurement apparatus.
Sources of Information
- 1929 British Industries Fair Advert p123; and p13
- 1937 The Aeroplane Directory of the Aviation and Allied Industries
- 1947 British Industries Fair p21
-  National Archives: A2A