Originally posted by: crazyrabbits
^

That would be a most excellent preservation effort.

And if your studio release has two discs and this CC DVD counts as the third, might as well buy some three-disc cases. Hell, I consider owning both the single disc ALIEN: 20th Anniversary and the 2-disc Collector's Edition to be a three-disc set. Fairly much all of these extras which aren't even on DVD which would be suitable for their own disc as I've already mentioned would be great for completists and for those who enjoy extra material content.
I wouldn't even need a custom cover, just disc label art pertaining to the concept I laid out. Perhaps a laserdisc and a DVD logo? Of course the top of the disc on the label art would be the films title and on the bottom would cover the Criterion Collection information. Sounds good to me.