concurring in part:
*86I concur in the result and in Judge Kashiwa’s opinion except for the part holding that the condition precedent to the Government’s right to extend the period of performance had not been fulfilled on October 4, 1969. I abstain from joining in that portion of the opinion because I believe that, if the Government had duly chosen to extend the time for another 12 months (which in fact it did not do), the extension would have been valid.