Oddly, in their Hellsing ones, they moved all of the end-of-volume extras (gag strips with the Valentine brothers, some of his old on-shot manga that featured characters that would go on to appear in Hellsing proper) to the back of the final Omnibus, rather than including them where they would've been in the single volumes.It became clear pretty quickly that these aren't edited to be like extra large continuous volumes, they're three separate volumes collected into one book, and they're just going to dump that content in there exactly as it would appear in any individual volume.