1. In lieu of issuing toll bridge revenue refunding bonds as provided for in section 234.220, the governing authority of any public agency now or hereafter having outstanding bonds issued under the provisions of sections 234.210 to 234.300, may, with the consent of the holders of such bonds, extend the maturity date or dates of such bonds and, with like consent, may also reserve the right to call in, pay and redeem such bonds on any interest payment date prior to the extended maturity date or dates thereof, and, with like consent, may also change the interest rate thereon. All such changes in the terms of such bonds shall be evidenced by proper endorsement or endorsements to be made on or attached to such bonds and by attaching to such bonds such appropriate interest coupons as may be necessary to evidence the interest to accrue thereon to such extended maturity date or dates. No such extension of maturity or reservation of the right of redemption prior to maturity, or change in interest rate shall be construed as changing or varying in any respect or to any extent any other terms or provisions of such bonds.

2. Upon the making of any such extension or extensions of maturities, or upon reservation of the right of redemption prior to maturity, or upon making any change of interest rate, the governing authority of the public agency by which such bonds were issued shall cause to be certified to the state auditor of Missouri, for filing in his office, a full transcript of proceedings and other documents relating to such extension, reservation or change, but such bonds, bearing such endorsement or endorsements and having such appropriate interest coupons attached thereto, need not again be registered by said state auditor.