(a) Regardless of whether there has been production of the severed mineral interest, if the owners of the severed mineral interests which are the subject of a trustee's lease executed and delivered in accordance with this Act remain unknown or missing for a period of 7 years from the date of entry of the initial judgment authorizing a lease, the trustee shall file a motion with the court on or before the eighth anniversary of the date of the lease naming the then present surface owners as additional parties defendant and requesting the surface owners to appear and present proof to the satisfaction of the court that they are vested with fee simple title to the surface estate. Upon a finding by the court that the surface estate is vested in fee simple in the surface owners, the court shall order the trustee to convey to the surface owners by recordable instrument the unknown or missing owners' interest in the severed mineral interests, which conveyance shall be approved by endorsement by the court on the face thereof.(b) The trustee shall pay to the surface owner the remaining balance in the depository which has accrued to the credit of such severed mineral interests to the date of his final report after payment of all allowable fees, taxes, expenses and court costs including a fee to be paid to the trustee in an amount determined by the court.(c) From and after the date of the conveyance from the trustee to the surface owners executed and delivered in accordance with subsection (a) of this Section the surface owners shall be entitled to receive all proceeds from the lease of such severed mineral interests.(d) Upon the delivery of the conveyance directed in subsection (a) of this Section, and after the payment as directed in subsection (b) of this Section the trustee shall make his final report to the court, and upon approval thereof, the court shall order the trust terminated and the trustee and his bond discharged.