Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 131,560 pages of information and 209,038 images on early companies, their products and the people who designed and built them.
1760 Company founded (question whether this applies to this company or the Northampton one of similar name).
1908 The Motor Show featured separate stands for English-built and French-built Lorraine Dietrich cars. The English-built machines were made in Birmingham. One had a specially-designed Mulliner cabriolet body; the other had an entirely enclosed carriage body by Salmons and Sons.
1914 H. H. Mulliners Ltd, motor car body builders of Broad St, Birmingham
1917 Acquired by Calthorpe Motor Co
1924 Private company. Calthorpe gave up making cars.
c.1928 Mulliners (Holdings) Ltd was incorporated
By 1929 Mulliners (Holdings) was a public company
1930-32 Annual reports in Coventry Archives
1953 Mulliners remained a public company
1961 Motor body builders for the motor industry. 1,800 employees. 
1974 Mulliners (Holdings) Ltd was dissolved