The rights and the remedies herein conferred upon or granted to the bondholders shall be in addition to and not in limitation of any rights and remedies lawfully granted to such bondholders by the resolution or indenture providing for the issuance of bonds. If the authority shall default in the payment of the interest on any of the bonds after the same shall become due, and such default shall continue for a period of thirty days, or if the authority shall default in the payment of principal after the same shall become due whether at maturity or upon any unrevoked call for redemption, or if the authority shall fail or refuse to comply with the provisions of this act or shall default in any agreement made with the holder of the bonds, the holders of twenty-five per cent in aggregate principal amount of bonds then outstanding under the indenture or bond resolution involved, by instrument or instruments filed in the Office of the Recorder of Deeds of the County of Dauphin and proved or acknowledged in the same manner as a deed to be recorded, may (except as such right may be limited under the provisions of any indenture or other agreement as aforesaid) appoint a trustee to represent the bondholders for the purposes herein provided. Such trustee or any trustee under any indenture or the fiscal agent under any resolution or other agreement may, and upon written request of the holders of twenty-five per cent (or such other percentage as may be specified in any resolution, indenture or other agreement aforesaid) in principal amount of the bonds then outstanding under such indenture or resolution shall, in his or its own name--
40 P.S. § 1600.307