Original proposal for a twin-engine biplane 11-place transport (Design C-251). Housed in a black card 3-hole folder. Three pages of typed description on blueprint paper followed by a "Characteristic Table" (specifications) and then two performance charts. Included in the lot are two large blueprints, both with 3-views but in different scales (43x33" and 55x33"). All good - very good. These "Golden Age" original items are very scarse and seldom offered.