If anyone needs a custom sized tongue and groove box I've written a routine for the Shopbot on Grasshopper that should be able to generate a moderately sized box of any dimensions with a lid that fits snugly on top. Just give me the three box dimensions and the material and we can make it happen. The cuts are very precise and the outcome should edify any material that's used from MDF to European multiply plywood. If the box is on the smaller side we can even use good old fashioned solid lumber.