Well the shell would be 2x 72inx23.25in, 2x 22.5inx23.25in, and 1x 70.5inx22.5in or 2x 72inx23.25in, 2x 22.5inx22.5in, and 1x 72inx22.5in, then do w/e you want for a door. im assuming your using 3/4 thick wood.

you have to waterproof mdf if you use it someway or another. melamine you just have to seal the corners.

you can take any cage design and make it bigger or smaller to fit your cage dementions