Doing one now. Made from a 1950's Case brand cotton trailer.
Ours is off wheel and turned upside down. Had some welding work done and am now doing the finish work. Dimensions are 16x8 for 15 hens.
That also gives me an idea....my brother-in-law farms...has many many acres of farmland..took it totally over after his father died. I'm sure he has many cotton trailers sitting around. Time for a nice visit with him. LOL
Living in the North, I'd never heard of a cotton trailer. They look perfect in every way for making chicken coops for all kinds of uses. You've really done a great job on yours. Keep the pictues coming.