I'm looking at this thread and your pictures a second time, Lance
, and I am still amazed this was your first Arduino project! Although it does seem like you have to have had some kind of chops under you belt; you have an o-scope, and there was programming and the custom circuit involved...so I have to ask:
Why are you a farmer and not a circuit nerd like the rest of us? ;D
Where did you pick up your skills? What made you decide to void the warranty on your tractor (does Case know about this?)...
LOL - actually, I like the custom enclosure for the Arduino and interface PCB - I think I have one in my fridge holding some leftovers! The only thing I would suggest (though you say you are moving to a different platform, and it seemed to have held up anyway) is to blob some hot glue on the i/o sockets and wires to/from the Arduino (and maybe the USB connection, too) - I am really surprised that the vibration and such didn't pop those loose! Really they should be soldered in place, rather than stuck in the headers.
Wow - great job!