well.. that's the full story
sn c119401
model id 31013c
date code 5b02
sn puts it as a 65 model.. starting sn for 65 was c100000, starting sn for 66 was c124000
date code decodes to
5 = 1965
B = febuary
02 = fed 02, 1965
C - afternoon shift
model id decodes to:
3 = 3000 before 4-68 ( agrees with date code and sn )
10 = ag chassis
1 = diesel
3 = live 540 pto
C = 8spd trans
31013C and it's post 4-68 counterpart a C1013C are probably the most common.. or at least desireable 3000's
thus you have a early 3000 not a 4000.
your machine is 3 cyl.. 175ci diesel ( as oposed to a 158 gasser )
less hp than either a 4cyl 4000 or a 3 cyl 4000 still decent hp though.. no problems with a 6' brush mower..