The court may in its discretion provide in said order that such payment to non-concurring holders may be made in installments, or otherwise deferred for a period of time if the amount so deferred shall not exceed 25 per cent of the net amount of the bid: Provided, however, That the full pro rata to be paid said non-concurring holders hereunder shall, in any event, be made within 18 months from the entry of said order. The sum so deferred shall bear interest at the rate borne by said bonds. No personal obligation for such deferred payment shall be imposed upon the trustee but such deferred payment shall be secured upon the right, title and interest acquired by the trustee as a result of such acquisition and shall be enforced as herein provided. If payment to said non-concurring holders shall not be made as provided in said order, the court may, upon application of any non-concurring holder to whom such payment shall not have been made, order the trustee to sell the property so purchased by the trustee, or such part thereof as may be necessary, either at public or private sale after notice thereof shall have been given to all interested parties in such manner as the court shall direct, and out of the proceeds of said sale pay the sums due said non-concurring holders, the balance, if any, to belong to the beneficiaries of the trust hereafter provided for and to be held and dealt with by the trustee as the court shall direct.