Ok, so I went back and checked, and there really is only 2 items instead of 3 from the merchandise store hiding in The Deadly Device. I checked the files and it looks like one item was moved, likely because it was in the way of an overlay image. (This overlay image needed to be viewable from several angles and it is likely that the item would have complicated this.) Oh well! Perhaps it will appear in a future game. 😉
To think backwards, some images from DED are in the merchandise store for you to design an item with. For example (and I just might get one of these myself because I love it), the Koko Mallos candy box image (found in Niko’s office) can be placed on a mouse pad, keepsake box, t-shirt, or *gasp* a pillowcase! It looks amazing, I think. It would be great to pair with the Koko Kringle pillowcase!
Oh, and of course, the Koko Kringle pillowcase is one of the 2 items placed in the game. 😉