I would GUESS its a 70 s kubota
I still have the manuals for it too.
I mowed my back field with it (15 acres) and it always did a good job. You sit really high in the seat which was really nice on tall grass.
Kubota called that tractor the (dollar a day tractor )
its 2 cyl.and they run very good, lots of power..
Ernie <><