Material deposited in 1967 contains four files containing the following:
- Typescript bibliography, thought to be for 'A Guide to British Historical Portraits for the use of Historians', c. 1935-c. 1940;
- Notes for bibliography, c. 1935-c. 1940;
- Correspondence, includes correspondence from Sir Henry Mendelssohn Hake (when Director of the National Portrait Gallery) and a copy of 'Collections of Historical Portraits and other forms of Iconography in Great Britain' by W. G. Constable (1934). Some Correspondence is in German. Correspondence spans 1935-1940;
- Undated notes and newspaper cuttings, some in German, c. 1935-c. 1940.
The material deposited in 1973 consists of research material created by Steinberg for a article or book on the portraits of George I. The material includes index cards, photographs and notes.