Item 72: Beurling, A. & Hewitt, E., An approximation method in non-compact spaces, with some application to harmonic analysis (pdf). Typed manuscript 27 pages (with Beurling's handwritten corrections). The paper begins with a general duality theorem, which Beurling gave in his NYU Lectures, item 71.
Item 76: Additive functions of intervals (pdf). Notes taken by L. Ehrenpreis. Theory of finite additive measure on R with applications to harmonic analysis. Not published, 51 pages. The page numbering had mistakes. Now the pages are hopefully in correct order. Several corrections in the text were made by Beurling. Some pages are difficult to read. Related to Beurling's approach to pseudomeasures. This note likely predated his C.R. Notes included in CW-2.