executed in connection with the sale by the Government, or any agency or official thereof, of any of the so-called Greenbelt towns, or parts thereof, including projects, or parts thereof, known as Greenhills, Ohio; Greenbelt, Maryland; and Greendale, Wisconsin, developed under the Emergency Relief Appropriation Act of 1935, or of any of the village properties or employee’s housing under the jurisdiction of Tennessee Valley Authority, or of any housing under the jurisdiction of the Department of the Interior located within the town area of Coulee Dam, Washington, acquired by the United States for the construction, operation, and maintenance of Grand Coulee Dam and its appurtenant works: Provided , That for the purpose of the application of this subchapter to sales by the Secretary of the Interior pursuant to subsections 3(b)(1) and 3(b)(2) of the Coulee Dam Community Act of 1957, the selling price of the property involved shall be deemed to be the appraised value, of any permanent housing under the jurisdiction of the Department of the Interior constructed under the Boulder Canyon Project Act of December 21, 1928 , as amended and supplemented [ 43 U.S.C. 617 et seq.] located within the Boulder City municipal area: Provided , That for purposes of the application of this subchapter to sales by the Secretary of the Interior pursuant to subsections 3(b)(1) and 3(b)(2) of the Boulder City Act of 1958, the selling price of the property involved shall be deemed to be the appraised value; or