I have a 30" MES and am thinking of smoking an entire ham, not a half or portion, but a whole bone in ham. I may be wrong but I don't think I could fit a 12-15lb ham in there? Doesn't seem all that big inside.
Trying to picture how wide a ham that size is. I would think that you could fit it on the 3rd or 4th rack down with the top racks removed. The outside width is just under 20 inches. I'd take a tape measure and first measure the width, height, and circumference of the ham and then check the available space above one of those two lower racks.