Cut some cardboard up and find some way to cross-brace the inside of it. Vertical smokers get damaged easily, even being shipped by the factory. Some 4" strips cut to length with a notch halfway through in the middle, to make a + should do it. Or maybe even a lot of packing material poured or stuffed into the corners of the box after it is packaged up.
Good find. Someone was probably hoping someone would find use for it. Around here I can set something remotely useable looking in front of the house and it's gone in ten minutes... as long as there's not a For Sale sign in front of it