ARRANGEMENT
§ 3.430 Fuel system arrangement. Fuel systems shall be so arranged as to permit any one fuel pump to draw fuel from only one tank at a time. Gravity feed systems shall not supply fuel to any one engine from more than one tank at a time unless the tank air spaces are interconnected in such a manner as to assure that all interconnected tanks will feed equally. (See also§ 3.439.)
CAR 3.430 of March 13, 1956. The wording of CAR 3.430 of November 01, 1949 is identical. My bold.
I cannot explain why the Aeronca Sedan fuel system does not conform, I just read what the requirement says. 'Sounds as though you clearly understand the intent of the design requirement.