Hey guys, so I picked up a snap on IN3815 top box that measures roughly 40" wide x 20" deep x 18.5" tall. The bottom is not flat, but rather has a stand off that seems like it probably registers in the top of the bottom box it would generally be set on. What I am trying to figure out is if snap on made a middle box that matches this top box and what the part number for it might be. I don't have a pic of the box I have, but this is an image from the web that comes up when I google the part number of the top box. There is basically no information available in this box. HELP!