That was one of my first firewood processing tool build projects. It's made of old posts recycled from a deck I built years ago and tore down less years ago.
The trailer has had at least 3 axle setups that I recall.
Its current iteration seems to work well.
Big enough to hold quite a load and not too big for the heavy Cinnamon Horse to pull.
A lighter weight tractor would be much less useful.
I've been considering adding width to the vertical posts but it works well right now.