I have a Brinkmann charcoal grill(pitmaster?) that I want to add a side firebox to. I can't find where Brinkmann sells the firebox separate and the Char-Griller side firebox attaches to the wrong side. I need one that attaches on the left side of the grill as you face it. Anyone know of a side firebox that would fit on the left side of this grill? Even if it is a different brand I could probably make it work with some alterations.