Don't try and clamp them with masking tape through the interior because it could damage your wallpaper. I have used masking tape before on wallpaper and generally it won't harm it, if the paper is thoroughly dry, but scrapbook paper is a little flimsier than real dollhouse wallpaper. The laser cut feature of the dollhouse will have such a nice and precise fit for parts that you won't need to clamp them anyways. Just make sure all tabs are tightly in their slots and there are no gaps around the walls.
As you can see now after the install, the bay is not that visible so wallpapering it would have been futile.
This little dollhouse is certainly coming together.
