The tank is busted up a bit from being in the creek. Not going to fill it. As for the size can't I just run the front burner with some fire bricks wedged in the forge to create a temporarily smaller space when needed? Worst case if the length is that big a deal I can easily drop three inches on each end reducing the total length to 13" inside. Buying a new 20lb tank to butcher is not going to happen. I would just assume get some sheets and refractory and weld up a box.
Wayne, been to your site and will be contacting you for supplies shortly. Just trying to figure out how much wool I need. Thanks.