Heat Exchanger, Refrigerator SVCE (511, 550)
  511     Use Prior to M/P964470.
          Use From M/P964770 to M/P1004774.
          From M/P964470 to M/P964769 use 7015850.
          Frm M/P1004775 to M/P1204689 use7015850.
          Starting with M/P1204690 use 7015951.
  550     Use From M681166/P612941 to M/P964069.
          Use From M/P964470 to M/P984749.
          Use From M/P985150 to M/P1004774.
          See 7015718 for Additional Serial Breaks