It appears you have a GRAY market tractor which Kubota Dealers will not get involved with.
The good news is that it has a USA equivalent model the B8200DT. This is a non hydrostatic transmission model and is not common.
Messicks, a major Kubota dealer has this parts illustration.
Messicks parts
007kubotaguy, a member on this site often has used parts so you may want to contact him
Dave