Here's my take. I built the bumper years ago then a recent tyre size upgrade prompted the build of the carrier:
I made a housing for some old kingpin bearings for the hinge & used an old car door latch which works great.
The socket & holes on the end accept a custom built bike rack. Or anything else I may think of in the future.
Next up I need to install a stay, put a spade mount in front of the tyre & add a reversing/camp light on an extendable pole.
Cheers
Clint
I like your setup. Those tires are rad, too. Are they the centipede tires? I think that's the name...
Bumper and Rotopax tire carrier I had made by a guy in Knoxville TN.