Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 137,377 pages of information and 220,926 images on early companies, their products and the people who designed and built them.
of 39 Victoria Street, London, SW1
James Elphinstone Baty was senior partner.
1937 Precision engineers. "Mercer" Dial Gauges, Measuring and Inspection Equipment. 
1939 See Aircraft Industry Suppliers
1940 Advert. Dial gauges. 
1945 Advert. Mercer dial gauges and measuring equipment. 
1960 Advert. Dial gauges.