As has been said, I would think that the parts for the Hinomoto might be a problem. As far as the Kubota goes, isn't it a gray market model? If it is, I don't see how they got it here.
Jerry,
It is a common scam to label it in Japan as a Zen-Noh and call it that on the paperwork. The problem is that if you ever get checked and customs sees Kubota on the tractor (steering wheel, instrument cluster ect) it can be a problem. Zen-Noh is a legitimate co-op and for years has privately labeled tractors legitimately but this was not one of them.