I made my own from the bottom of a keg (i flipped the keg upside down to bottom drain the MLT). I hit it with a angle grinder, and 20 min later it was done. Not nearly as snazzy as dutchoven's (very nice job btw), and maybe a touch harder to use, but it works well enough.
p.s. if you make your own, don't drill the holes. It'll take forever. Cut slits in it.