Bought a File from Etsy, but not sure what size material

I am trying to build a Candy/ Cupcake Cart for my Moms 70th Bday/Retirement Party. I found one on etsy for a Flat pack design. However the website doesn’t state what thickness of material they used. thought maybe there would be some information after purchase … not so much. These files are also set up for Laser, so I am going to have to modify them to space the pieces apart a bit. However If someone could look at this file, and maybe tell me the size of the Cutouts are for the Tabs to slide and lock into.

ETS071-LAYOUT (50x36)-1.DXF (46.0 KB)

According to the notch, the thickness of the material should be 15mm. When using CNC machining, just pay attention to the notch needing to be overcut.