For a period of not more than fifteen years after August 4, 1955, or, in the case of Los Alamos, not more than fifteen years after the date it is included within this chapter, the Commission shall indemnify the purchaser (except a purchaser taking advantage of the provisions of section 2326(d) of this title), and any successor in title, of any such single family or duplex house as set forth in this subchapter. This indemnity shall be deemed to be incorporated in the deeds given on the sale of Government-owned houses. One person may not invoke the indemnity in respect of more than one house.