I think this looks eerily lovely unpainted. The surface is so smooth and the proportions are perfect. You could consider selling individual jointed figures of the ponies like this maybe? Just an idea, but the automatons (I hope that's spelt right) are always enchanting.
I had to laugh, you just... FOUND it? Like, you forgot about it and the ridiculous amount of hours put into it, and then it just popped up again? That's hilarious, now you have to think of something to do with it.