Parts are available but OEM parts will have to come from Japan. I have seen these for sale many times but have stayed away. There use is in dairies so they almost always have high hours and the floors are rotted out due to mud on the operators boots. Feed lots are mucky places especially in Japan. The V series Shibauras and MT series Mitsubishis always seem to be in better shape and have lower hours. I have no idea why that is either
Dave is right it is a FxxD model. Looks like 70hp to me so I would guess an F60D or F70D. Also looks like it is still in Japan. This size tractor I would only buy from a dealer who knows how to repair and support them. Problems can get spendy.
Buck