4. Stocks, bonds, notes and other evidences of indebtedness of any county, city, town, district, authority or other public body in the Commonwealth upon which there is no default, provided that if the principal and interest be payable from revenues or tolls and the project has not been completed, or if completed, has not established an operating record of net earnings available for payment of principal and interest equal to estimated requirements for that purpose according to the terms of the issue, the standards of judgment and care required in Article 9 (§ 64.2-780 et seq.) of Chapter 7 of Title 64.2, without reference to this section, shall apply. In any case in which an authority, having an established record of net earnings available for payment of principal and interest equal to estimated requirements for that purpose according to the terms of the issue, issues additional evidences of indebtedness for the purposes of acquiring or constructing additional facilities of the same general character that it is then operating, such additional evidences of indebtedness shall be governed by the provisions of this section without limitation.