I'm thinking on a propane verticle smoker. I found what I thought to be a deal a Char Broil, On CL. Research shows the shelves are 13 3/4 square. Kinda small for the traditional Thanksgiving Turkey. Masterbuilt 30 and 40 only tell total cooking surface, which seems to work out to about the same if they and I do the math right. I find the editing/proof reading on many sites are somewhat lacking. Can someone measure and post the actual shelf sizes for their MPS 30 or 40 ?