Fuwa Fuwa over on the Funkofanatic forums recently purchased these two prototypes off of Gemini Collectables, both hailing from the same set.
And in other news, we haven't completely confirmed this yet, but someone noted that the Funko booth at Comic Con was announcing a set of Rainbow Dash, Derpy, and Vinyl Scratch for Hot Topic. Again though, this was quite a while ago, and we don't have any tangible evidence for it, but so far it does fit the mold on what Hot Topic is actually carrying. Derpy, Scratch, and Rainbow are pretty much their big three.
Thanks to Christine and Valeria for the tips!