The only personal information about Sylvester E. Strittmater is a collection of membership cards which illustrate his interest in hunting and other organizations. Items represented (1964-1972) are the National Rifle Association, Holmen Shooters Club, Mississippi River Rates, Knight of Columbus, and the Benevolent and Protective Order of Elks (BPOE).

Gateway Die & Tool Company materials (1944-1949) include a folder of ephemera which includes a sample of letterhead and Sylvester Strittmater's business cards. There are also two financial volumes of the company; one of a day-book format, 1944, and the other covering invoices 1945-1949.