It doesn't sound as though you have the proper number. The number should be located on the instrument panel below the steering column as shown at tractordata.com. You should check it out!
What year is a massey ferguson 165 with a serial number of 37786240?
what year is massey ferguson 240 with a serial number of b17204
year of massey ferguson 35 with serial number 251807
1968 http://www.masseyfergusontractorparts.net/Massey-Ferguson-tractors/2008/06/massey-ferguson-135-serial-numbers/
1968 http://www.masseyfergusontractorparts.net/Massey-Ferguson-tractors/2008/06/massey-ferguson-135-serial-numbers/
1964
1974
1973
mf35
1971
1976
1964