Yeah, his proportions are a tiny bit wonky, but I do love my MP-5!
And yeah, the only third party accessories I know of for him are the previously mentioned ones which, as you may have noticed from my photos, I have.
That all being said, as much as I do love him, if they made a new one in the new Masterpiece scale, that was still a gun, and that like the MP-10 improved the accuracy of the look of the figure, and that was more sturdy then MP-5, and
(since, like MP-5, it would be likely to be a Masterpiece mold that wouldn't be released domestically) the cost to import one wasn't too
hideous... well, I'd jump all over that!