(1)  On payment of such compensation, or on executing such agreement, or on making a reference under section 64, the Collector may enter upon and take possession of the land, and use or permit the use thereof in accordance with the terms of the said notice.

   (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 shall proceed under this Act to acquire the land as if it was needed permanently for a public purpose.