Heres a quick trailer. Took me an hour to build, it works good:
Ingredients:
2x2 piece of 1/4" plywood.
piece of conduit bent in two dimensions by eye.
a conveniently sized chunk of metal with flanges off an exercise machine.
left over adult sized training wheels.
carriage bolt & eye bolt and locking nuts (enough slop to lean).
bunch of self drilling screws.
Though I love the alicestrong trailing cart post
Played that one out a few times in my head.