Good point - I did EXACTLY that and love the change! The tiny tool box couldn't hold half of what I used regularly. I got a large weatherproof box, hammer, sockets and ratchet, screwdriver, etc, and now have plenty of room for everything.
Also forgot: some sort of weatherproofing for the pins that hold the 3-point hitch. You need to remove them sometimes, depending on what you're putting on the back (i.e. backhoe) - I had one get rusted into place once and it was a major pain to remove. I got some sort of grease from my dealer that's made a big difference (not near it or I would check exactly what it was)