Two weeks to the day I got a tire. Kubota (finally) sent a wheel assembly (tire/rim).
If you know someone looking for a rim I have one, or a tire 21 X 8:00 x 10, Davis Equipment (Ashland, KY) has several now in stock. . . I guess all that exists in the USA!
I'm back in the saddle again, but still not happy with the poor customer service from Kubota.