Could you go into details why it did not work?? I'm thinking about Pat's but if it doesn't work on everything... forget it.
The shape of the ballast box is the problem. The box is narrow at the bottom and wider at the top, just above of the pins the box begins to taper up and this taper does not allow the Pat's to connect. It is not a fault of the Pat's but rather poor design from Kubota. I've considered looking for a JD ballast box since they appear to be square/rectangular and the Pat's would work fine.
If you would like a pic let me know, I'm heading up there tonight after work and can snap one.