Here is a video of Andrew Dwyer cooking a couple of chooks in an 18 inch Bedourie Camp Oven.  There are not many that size around.  You will note that the lid is quite warped on it.

After seeing the video many years ago I contacted Andrew to ask him where he got the oven from and he told me my old mate Bill Thompson at Southern Metal Spinners had made it for him.

I gave Bill a ring and he told me he only made a few to see how they would go as there was nothing they could do, due to the size, to stop the lids from warping.

I often wonder what happened to them all.

https://www.youtube.com/watch?v=ONAU7u_1NLA