I hope everything went well with Elliot. I have a skinny cat too. My cat, Kitten, is a black cat that I swear has Russian Blue in his lineage. Everything about him screams Russian Blue- his slim, sleak body, the shape and look of his head, ears, etc., and he has the attitude of a Russian Blue. The only thing with Kitten that doesn't suggest Russian Blue is that his fur is BLACK! Oh, and every Russian Blue that I've met has the same meow as Kitten. Anyway, Russian Blues are thin cats by nature, my bet is that Elliot is that way too. (I know others have suggested that too.) I hope that's the case anyway.