Alrighty. So the part number for your light bulb and not kubotas number is 6260ba. That number should be good for every major manufacturer whether it be sylvania, wagner,eiko. Of course that's just what I've found poking around.
However, that is not a common bulb at all. Which means virtually zero aftermarket support. However if your inclined you might take that old one to a store and compare it to an h7. They look to be close to the same size and use similar connectors. They do have some alignment tabs that you might have to snip off. Just don't touch the glass.