the present value of all amounts thereafter payable as compensation, such present value to be computed in accordance with a schedule prepared by the Secretary, and the present value of the cost of all benefits thereafter to be furnished under
section 907 of this title, to be estimated by the deputy commissioner, and the amounts so computed and estimated to be retained by the employer as a trust fund to pay such compensation and the cost of such benefits as they become due, and to pay any sum finally remaining in excess thereof to the person entitled to compensation or to the representative; and