Thanks for the quick reply. I need a box that is roughly 4"x12" with a
height of 2'+. Cylinders, although easy to come by especially in
stainless, create problems with trying to get heat to all the beans.
That's why the ammo boxes caught my eye in the first place. I would
only need to fab one piece and drill two holes to get to what I need.

Stainless is what I thought of first but I was floored by the price of
stainless sheet. I even thought about cutting an SS cookie sheet and
the pieces reassembled.

Perhaps you or someone else has some suggestion for materials that
wouldn't break the bank. I would like to keep this part of the project
under $75. I know that's not much and it's a one-off sort of thing but
I'm just trying to tinker and don't want to set the wife off on what
was supposed to be a cost cutting measure long ago.