U.S.C. 1712 ). 5. Equalization of the exchange (a) Appraisal (1) In general Not later than 18 months after the date of execution of the exchange under section 4, the total value of the land exchanged shall be determined by an appraisal in accordance with paragraph (5) of the Agreement, that shall— (A) be based on land and mineral values determined as of the date of enactment of this Act