Any individual Indian owner of trust or restricted lands, may with the approval of the Secretary execute a mortgage or deed of trust to his land. Prior to approval of such mortgage or deed of trust, the Secretary shall secure appraisal information as he deems advisable. Such lands shall be subject to foreclosure or sale pursuant to the terms of the mortgage or deed of trust in accordance with the laws of the State in which the lands are located. For the purpose of foreclosure or sale proceedings under this section, the Indian owners shall be regarded as vested with unrestricted fee simple title to the lands (Act of March 29, 1956).