Do whatever you want, OP. There's nothing wrong with cleaning this up with a fresh coat of paint. I'm guessing the inside looks as dirty as the outside, and personally I wouldn't store my tools in something that dirty when I could just as easily clean it up. Also, it does appear that there's rust starting to creep in at the seams. Better to nip that in the bud before it spreads.

All of the reasons from animal foundations that I've read revolve around human nature and the psychology of rewards in general. If you want to believe that animal groups are the end-all, be-all authority on human nature and psychology, go right ahead.

For people who see this cat as something they could sell (because it's an expensive type of cat), you need to give them incentive to return it rather than sell it. There's a reason cash rewards have been given forever.