Kit,Hot Gas Replacement SVCE (601F, 501F)
  601F    Use Prior to Serial #1810000.
  501F    Use Starting with #M/P1004775 & between
          #M960170-M960319 and #M996400-M996574.
          Prior to #M/P1004775 except between
          #M960170-M960319 and #M996400-M996574
          see 4201090