In any suit, action or proceeding by or on behalf of the holders of defaulted bonds of a city brought under this act the fees and expenses of a trustee, including operating costs of a project and reasonable counsel fees, shall constitute taxable costs, and all such costs and disbursements allowed by the court shall be deemed additional principal due on the bonds, and shall be paid in full from any recovery prior to any distribution to the holders of the bonds.
53 P.S. § 15921