Leyland Innocenti Mini Cooper 1300 Export production dates:
Feb '73 upto Jan '75

 CHASSIS No. B39/7-..........
 ENGINE No.:
     12H-610/635-X (11 stud cylinder head and duplex driving gear)
     12H-719/832-X (11 stud cylinder head and single driving gear)
 NUMBERS BUILT   28,200
 DATES CHASSIS No. Monthly production
 FEBRUARY '73 540001-541227 1227
 MARCH 541228-542453 1226
 APRIL 542454-543679 1226
 MAY 543680-544905 1226
 JUNE 544906-546131 1226
 JULY 546132-547357 1226
 AUGUST 547358-548583 1226
 SEPTEMBER 548584-549809 1226
 OCTOBER 549810-551035 1226
 NOVEMBER 551036-552261 1226
 DECEMBER 552262-553487 1226
 JANUARY '74 553488-554713 1226
 FEBRUARY 554714-555939 1226
 MARCH 555940-557165 1226
 APRIL 557166-558391 1226
 MAY 558392-559617 1226
 JUNE 559618-560843 1226
 JULY 560844-562069 1226
 AUGUST 562070-563295 1226
 SEPTEMBER 563296-564521 1226
 OCTOBER 564522-565747 1226
 NOVEMBER 565748-566973 1226
 DECEMBER TO JAN 2nd 1975 566974-568200 1227
   

If you spot any mistakes or have some more data i can add here please email me.