I've got a utility bed for a pickup truck out back. I long ago decided not to install it on the planned truck. I bought a new truck with a utility bed instead. I've since sold that truck, and the truck I was going to do the bed swap on, but I still have the utility bed. For a while I've been thinking about turning it into a trailer. Something I can load up with stuff on the rare occasion I go help a buddy doing handy man type stuff. With the right tires and axle it might also double as an over lander, although I doubt I'd use it that way... more than once or twice anyway. I have an axle, actually two of them, I took off the gooseneck last year when I installed a pair of new axles with actual modern electric brakes. I just didn't know where I was going to get the steel to make a frame for it. I might only use it a couple times a year. Its not like I plan to get back into contracting.
In my scrounging for steel I didn't mind wasting to build that winch plate project I walked around back of the shop and saw several long pieces of C-channel laying on the back work slab I totally forgot about. A buddy had a fire at his hotel several years back which damaged a couple parking shades. Part of helping him clear it up was hauling off the some c-channel. I think it was part of the no longer function parking shades. Not functioning due to being vaporized by fire. I totally forgot about having that channel.
I actually have everything I need to turn that truck bed into a trailer, and being a utility bed I won't have to show a dismantling permit to the DMV. An OEM bed is "part of the truck, but a utility bed is a bolt on accessory. Just register the whole thing as a home made trailer.
Well, there is one thing. I asked about it some time back for some other project. How do you bend c-channel in a home shop?
The only thing I can think of is to cut notches in the flanges. Get the web red hot, and bend it around a couple parking bollards. I have bollards protecting the building next to my over head doors on the shop. V it out, weld, grind flat, and weld on a truss plate over the welded beam top and bottom.