Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,405 pages of information and 233,863 images on early companies, their products and the people who designed and built them.
of 39 West Campbell Street, Glasgow and of Johnstone, Glasgow were makers of machine tools
1877 Company established.
c1887 Acquired A. McArthur and Son
1900 32 inch Double-headed Shaping Machine
1904 Incorporated as a limited company.
1904 Acquired the tool making business of Sharp, Stewart and Co
1911 Small portable drill
1914 Machine tool makers and contractors for engineers' stores, materials etc. Specialities: high speed machine tools for railway workshops, marine and general engineering. 
1937 The Scottish Machine Tool Corporation was formed by amalgamation of: James Bennie and Sons Ltd., G. and A. Harvey, Glasgow; Loudon Brothers Ltd, Johnstone; Craig and Donald Ltd, Johnstone; and James Allan Senior and Sons Ltd, Glasgow; all retained their separate autonomy, even though they had amalgamated.  
Note: Kelly's 1891 Post Office London Directory includes an entry for Loudon Brothers, engineers and machine tool makers (James Edward Darbishire, agent), 110 Cannon Street, London, EC.