(1) The refunding bonds may be sold or exchanged in installments at different times, or an entire issue or series may be sold or exchanged at one time. Any issue or series of refunding bonds may be exchanged in part or sold in part in installments at different times or at one time.
(2) The refunding bonds may be sold or exchanged at any time on, before, or after the maturity of any of the outstanding notes, bonds, certificates, or other obligations to be refinanced thereby.