(2)On the expiration of the term, the Collector shall make or tender to the persons interested compensation for the damage (if any) done to the land and not provided for by the agreement, and shall restore the land to the persons interested therein:Provided that, if the land has become permanently unfit to be used for the purpose for which it was used immediately before the commencement of such term, and if the persons interested shall so require, the [appropriate Government] [Substituted by A.O.1950.] shall proceed under this Act to acquire the land as if it was needed permanently for a public purpose or for a company.