Notwithstanding any provisions of this Act [sections
1941 to
1941y of this Appendix], in the event that the recommended sale of any facility is disapproved by either House of the Congress, any prospective purchaser of any other facility shall have a period of thirty days after the termination of the period for review by the Congress in which to reject the recommended sales contract with regard to the facility or facilities which he has agreed to purchase: Provided, That if as a result of the disapproval by either House of the Congress of the sale of any facility or facilities, or as a result of the rejection of one or more sales contracts by any prospective purchaser as provided in this section, the remaining facilities to be sold will in the aggregate not be capable of annually producing at least 500,000 long tons of general purpose synthetic rubber and at least 43,000 long tons of butyl rubber, then no facility shall be sold under this Act [said sections], and for the purposes of this Act [said sections] the report of the Commission shall be deemed to have been disapproved in its entirety.