Yes, those two work also but they are completely different than the one that was available from the main page. I believe it is the legacy parts system.
I initially thought that too but I've played with it a bit this afternoon and the problem only occurs if you initially select Agriculture. If you select Lawn and Garden it works as it should. Even stranger is I don't know why JD even has you make the selection as regardless of whether you initially choose Agriculture or Lawn and Garden you have access to the same parts sections.The legacy parts system is slated to go away. Maybe there are implementing that now?